Chevy

Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

2002 Chevy Tahoe. It runs and idles fine until hard

Customer Question
acceleration, or going up a...
2002 Chevy Tahoe. It runs and idles fine until hard acceleration, or going up a hill. Removed the cats, and o2 sensors because the guy I got from told me they were clogged. That didn't make a difference. It is still stalling from stepping on it hard. There was a code for flex fuel sensor, but I cleared it. I've driven for around 50 miles since clearing the code. The check engine light is back on, but that p0179 code is not showing. There are codes for o2 sensors and cats.
Submitted: 5 months ago.Category: Chevy
Show More
Show Less
Ask Your Own Chevy Question
Answered in 34 minutes by:
11/12/2017
Chevy Mechanic: Michael Solis,
 replied 5 months ago
Michael Solis
Category: Chevy
Satisfied Customers: 433
Experience: Lead Tech at Solis Auto Repair
Verified

Hello, my name is***** will be helping you out! I have over thirteen year of experience in the automotive industry for numerous different makes & models. I enjoy doing what I do, it is my life.

The first step we can attempt if you like is diagnose the code you just showed me, it could possibly be the issue you are experiencing as well.

It is a fuel related sensor, so it could be causing a stall or buck type of issue I just can not guarantee you that is the problem, but its highly possible it will be your problem.

If the problem continues after our diagnoses, then we will then have to have a fuel pressure

Is this thing a flex fuel? Can I have VIN if possible to make sure I am looking at my diagrams and trouble codes procedures accurately?

Ask Your Own Chevy Question
Customer reply replied 5 months ago
The vin number has the Z on the 8th place. I can see the flex sensor. I did a fuel pressure test. I plugged the gauge, and turned the key to on then off. While on it was going to a line below 50 and immediately dropping to 20 psi once key was off. I'm just not sure if it could be the fuel pump.
Chevy Mechanic: Michael Solis,
 replied 5 months ago

Ok so you did a fuel pressure test? Showed 50, then dropped to 20 correct? Yes this is a flex fuel then.

Ask Your Own Chevy Question
Chevy Mechanic: Michael Solis,
 replied 5 months ago

Can you also give me the short fuel trim along with the long term fuel trim data readings from your datastream please. Let me know if you do not understand this question :).

Ask Your Own Chevy Question
Customer reply replied 5 months ago
That is correct I did the fuel pressure test using a gauge from AutoZone and got 50 with key on and 20 immediately after turning the key off. I don't have such fuel data.
Chevy Mechanic: Michael Solis,
 replied 5 months ago

ok so you do not have a scan tool on freeze frame data it shows no fuel trim?

Ask Your Own Chevy Question
Chevy Mechanic: Michael Solis,
 replied 5 months ago

What about start up after shutting off, is everything seeming normal? Or does it have a longer crank or something abnormal it is doing other then what you have already stated?

Ask Your Own Chevy Question
Customer reply replied 5 months ago
I don't have a scan tool. I got the cat and o2 sensors from AutoZone. A friend of mine let me use the scanning tool but he took it back. Also while running I unplugged the flex fuel sensor, and it had no effect at all. I also tested the wire voltage and the wiring showed the right voltage of 12 volts.
Chevy Mechanic: Michael Solis,
 replied 5 months ago

You did not complete the full test procedure just by checking 12 volts, so you have a voltmeter that way we can run other test I will provide you?

Ask Your Own Chevy Question
Customer reply replied 5 months ago
It turns right on just fine. No hesitation whatsoever. As soon as you press hard on the gas , it stalls while sputtering. Then I have to wait for a few to start because it does not start right away once it stalls.
Chevy Mechanic: Michael Solis,
 replied 5 months ago

You are also going to have to get your buddy's scan tool again so we can run a 3rd test as well. Scan tool first is always the best way to start this procedure to test the fuel sensor

Ask Your Own Chevy Question
Customer reply replied 5 months ago
I've been trying to get the scanning tool from him but he has not been available for a few days. I know I did not complete the full diagnostics by getting 12 volts. Yes I have a voltage meter.
Customer reply replied 5 months ago
I've read a lot about this issue and other people with the same truck have said that with the bad sensor it only affected gas mpg. They said nothing about stalling at hard acceleration or going up hills. That is why I was leaning towards fuel pump but not sure, hence why I'm seeking advice.
Chevy Mechanic: Michael Solis,
 replied 5 months ago

No problem, we will run other tests without it in the mean time, just understand it makes this job of checking a lot more time consuming than it should be.

If we had the scan tool all we needed to do is see data stream of how many Hz or frequency it was showing, it should indicate 50 Hz if you are running on pure gas and 150 Hz if you are running on pure ethanol. If the readings are off in the data stream, the sensor is bad.

First, I want you to test your ground, if ground is good then check continuity on the computer wire (see attachment) if that is good, then our wires are all good.

Second, if all wires are good, then we can remove the sensor and see if there is any restriction visually when we put key on, (you will know it is restricted when you see it)

THIRD, would be looking at the data stream and will immediately tell you bad or good.

It is a fuel related sensor, it will affect the fuel system if the sensor is glitching out, it will make the ECM freak out and not accurately do its job either in the fuel air ratio bc of the Hz it reads, so yes it will affect your fuel system :).

Ask Your Own Chevy Question
Chevy Mechanic: Michael Solis,
 replied 5 months ago

And based on the fuel readings, we can not say fuel pump is good or bad yet, fuel pump is still a possibility.

Ask Your Own Chevy Question
Chevy Mechanic: Michael Solis,
 replied 5 months ago

Let me know if any of it makes no sense, maybe we can talk on the phone or describe it better here :).

Ask Your Own Chevy Question
Customer reply replied 5 months ago
I will try using the scanning tool which will be easier for me.
Chevy Mechanic: Michael Solis,
 replied 5 months ago

Sounds good, but you still have to check for that fuel restriction on the sensor AFTER seeing the Hz off in the data stream. If there is fuel restriction or slow fuel running through the line, then the reading will be wrong always. Likely though, the sensor is bad.

Ask Your Own Chevy Question
Chevy Mechanic: Michael Solis,
 replied 5 months ago

If you have time, please leave me a rating, it gives me credit for the answer and would mean so much to me :). It was my pleasure helping and we can still continue after rating, I will still be here for you.

Ask Your Own Chevy Question
Was this answer helpful?
Ask Michael Solis Your Own Question
Michael Solis
Michael Solis
Michael Solis
Category: Chevy
Satisfied Customers: 433
433 Satisfied Customers
Experience: Lead Tech at Solis Auto Repair

Michael Solis is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money.

Todd LRochester NY

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

< Previous | Next >

Meet the Experts:

GM Tech (Cam)

GM Tech (Cam)

Chevy Technician

15,289 satisfied customers

GM Grand Master Technician 2007. 14 years experience.

Gary

Gary

Chevy Technician

9,357 satisfied customers

15 years GM master tech

Tim&#039;s Auto Repair

Tim's Auto Repair

mechanic

8,866 satisfied customers

Have owned a repair shop for 25 yrs.

Dave Nova

Dave Nova

Chevrolet Technician

7,092 satisfied customers

ASE Master Certification. GM World Class Certification

John

John

Master A.S.E Automotive technician

4,071 satisfied customers

A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician

Don - Mo Lurch

Don - Mo Lurch

Auto Mech / Electronics

2,918 satisfied customers

Chevrolet Cert., Heavy Line Mech, Race Shop Owner, Mobile Electronics.

Ron Z.

Ron Z.

- Chevy Tech -

2,734 satisfied customers

18+yrs experience. State Inspector and Chevy Diagnostics

< Previous | Next >

Related Chevy Questions
Is the Chevy Tracker 2.6 liter an interference engine.
Is the Chevy Tracker 2.6 liter an interference engine. … read more
Gary
Gary
Chevy Technician
Vocational, Technical or Trade Scho
9,357 satisfied customers
The asr and the service engine light is on. 1993 Chevy
The asr and the service engine light is on JA: Do you have the trouble code? Do you have a code reader or scan tool? Customer: No JA: Not a problem. You can work with the Chevy Mechanic to figure that… read more
Amedee
Amedee
Automotive Consultant
Vocational, Technical or Trade Scho
18,833 satisfied customers
ABS LIGHT AND CHECK ENGINE LIGHT FOR MISFIRES ON ALL
ABS LIGHT AND CHECK ENGINE LIGHT FOR MISFIRES ON ALL CYLINDERS … read more
Mechanic01
Mechanic01
2,358 satisfied customers
My 8.1 vortex chev engine in a 5500 truck. 2004. The engine
My 8.1 vortex chev engine in a 5500 truck. 2004 . The engine quits like you shut it off it restarts right away and runs good. This happened 7 times in 200 miles. … read more
Roy
Roy
shop foreman
Associate Degree
4,111 satisfied customers
The 1983 Chevy C10 305 engine will not start. this is the
The 1983 Chevy C10 305 engine will not start. Roy this is the truck that has had a rebuilt engine installed, new alternator, starter and every other part I could think of replacing by a mechanic. Now … read more
Roy
Roy
shop foreman
Associate Degree
4,111 satisfied customers
2003 chevy silverado 4.8 engine reduced engine power light
2003 chevy silverado 4.8 engine reduced engine power light comes on no power … read more
GM Tech (Cam)
GM Tech (Cam)
Chevy Technician
Vocational, Technical or Trade Scho
15,289 satisfied customers
Rough idle and surging engine power, then the service
Rough idle and surging engine power, then the service traction control/stabilitrac system comes up and check engine light flashes. My check engine light has been on for a while because of evap codes. … read more
Mike V.
Mike V.
technician
Subaru and Nissan factory training.
26,373 satisfied customers
It's a fuel issue the engine cranks but will not start. I
It's a fuel issue the engine cranks but will not start. … read more
Mike S.
Mike S.
Vocational, Technical or Trade Scho
7,702 satisfied customers
Running engine stops or attempt to start engine fails, in a
Running engine stops or attempt to start engine fails, in a manner consistent with fuel starvation. Recently solved by installation of new fuel pump/sender unit, Problem has resumed approx two months … read more
Jerry Newton
Jerry Newton
Vocational, Technical or Trade Scho
5,346 satisfied customers
Well, the check engine light comes on and then I get a
Well, the check engine light comes on and then I get a warning that stabilitrack needs service and it is off. Also a warning that the engine power is reduced. Got oil changed and it didn't do this yes… read more
GM Tech (Cam)
GM Tech (Cam)
Chevy Technician
Vocational, Technical or Trade Scho
15,289 satisfied customers
I have engine on and will not start. It have a reduced
I have engine on and will not start JA: Have you checked the battery, particularly the terminal connections? Are they corroded? Customer: It have a reduced engine light on JA: What is the model/year o… read more
David Craig
David Craig
OWNER/MECHANIC
Associates
5,024 satisfied customers
There is a tick in the motor, check engine light is on. I
There is a tick in the motor, check engine light is on. I have ran an OBDII scanner and received to 3 codes one of which is pending. So the the main two are P0341 & P0342. We have replaced the camshaf… read more
Todd Audette
Todd Audette
Automotive Technician
Vocational, Technical or Trade School
351 satisfied customers
Engine rattle noise when cruising on V4 to V8. Front engine;
engine rattle noise when cruising on V4 to V8 JA: Where exactly do you think the noise is coming from? And how long has this been going on? Customer: Front engine; 3-4 weeks JA: What is the model/year… read more
Todd Audette
Todd Audette
Automotive Technician
Vocational, Technical or Trade School
351 satisfied customers
Check engine light is on and autozone checked with their
check engine light is on and autozone checked with their computer code P2135 then it triggered code P0017. For P0017 this was already addressed as they changed a part for it already. … read more
Jerry Newton
Jerry Newton
Vocational, Technical or Trade Scho
5,346 satisfied customers
The check engine light is on. The code is P1810. It is a
The check engine light is on. The code is P1810. It is a 2006 Chevy 1500. … read more
Ron
Ron
Automotive Tech
Vocational, Technical or Trade Scho
19,589 satisfied customers
Started engine with remote! Engine ran for about ten seconds
Started engine with remote! Engine ran for about ten seconds died,tried with the key won't start ! Checked fuel pressure on a shrader valve ! No fuel!? … read more
Gary
Gary
Senior Technician
Vocational, Technical or Trade School
88 satisfied customers
1989 5.7 liter throttle body engine. I was driving, engine
1989 5.7 liter throttle body engine. I was driving, engine was running fine, and came to stop sign. Upon trying to accelerate from the stop, the engine would hardly run. Bad miss and backfire visible … read more
rpmdiag
rpmdiag
High school
7,492 satisfied customers
The reduce engine message and the engine light on and alot
the reduce engine message and the engine light on and alot if shacking when I started it this morning … read more
Jared D
Jared D
Shop Supervisor
Bachelor\u0027s
2,128 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x