Jeep

Have Jeep Questions? Ask a Jeep Repair Expert for Answers

Ask an Expert,
Get an Answer ASAP!

Jeep

Story short, customer requested refurbished heads with new

Customer Question
Long story short, customer requested...
Long story short, customer requested refurbished heads with new timing components. One of my mechanics performed the repair with repairs to the heads and all new timing components. vehicle started upon completion but it ran exteremly rich, & and smelled like bad catalytic converters. When I pulled up the graphing data on the scan tool I noticed something very interesting. It's displaying a current sync (2) that's switching back n forth between ok & sync lost with only the ignition on. Current Sync (1) is a solid OK. Replaced cam & crank sensors with no change. What else I noticed was interesting was the MAP sensor is reading 3.7v, coolant volts @ 4.5v, IAT @ 4.98, left & right exhaust reading rich, all 4 oxygen sensors (this is a California model) reading around 4.9v, oil pressure @ 4.57v, sensor reads 70psi when unplugged pressure goes to 0 but still reads 4.57v on graph. All these readings are with engine off ignition on. Vehicle struggles to keep running and the cats get exteremly hot after running for a short amount of time. Has the sulfur smell to it. No codes are coming up at this time. Thinking maybe a wiring issue?
Submitted: 1 year ago.Category: Jeep
Show More
Show Less
Ask Your Own Jeep Question
image.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpgimage.jpg
Answered in 7 hours by:
3/9/2016
Jeep Mechanic: Juan Crespo, ASE Certified Technician replied 1 year ago
Juan Crespo
Juan Crespo, ASE Certified Technician
Category: Jeep
Satisfied Customers: 1,529
Experience: A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European
Verified

Do you still need help with this?

Ask Your Own Jeep Question
Customer reply replied 1 year ago
Yeah please :). No access to wiring schemitcs right now and it's driving me a little crazy haha
Jeep Mechanic: Juan Crespo, ASE Certified Technician replied 1 year ago

Well, I would also go crazy looking at those screens. Sometimes we need to take a step back and regroup. So let's do that, shall we?

We know the engine starts and runs, so we can eliminate all the systems and components asocciated with that function. What we have left is an engine running rich and a lot of weird data from the PCM.

Out of all that weird data, one jumps at me as being particularly weird, and that is O2 voltage at 4.9 volts. In my experience, I've only seen that happen in vehicles where the O2 harnesses had been touching the hot exhaust pipes. So, were I in your shoes, I would put that Solus down and start checking those harnesses. If those check out OK, and you might have to pull out your Ohmmeter to verify they are indeed OK, then keep going through all the sensor circuits starting at the sensors themselves and all the way up to the PCM.

It is highly probable that the problem is in the wiring, but if every circuit tests out OK, then I would have to say the computer is shot - it's just that I haven't seen many computers going bad on their own, if you know what I mean ;-)

This one seems to be challenging, please let me know what you find.

NOTE:

Remember that what you see on graphing scanner screen is just an interpretation of the signals being sent by the onboard computer. The actual signals, may they be in from a sensor or out to an actuator, can only be accurately checked at their source with a meter or scope.

Ask Your Own Jeep Question
Customer reply replied 1 year ago
Sounds great, in the morning I'll go ahead and do a close check of the oxygen sensor wires around the exhaust pipes. I'm gonna go ahead and peel back the sleeve to ensure nothing is burnt :). I'll let you know tomorrow!
Thanks
Jeep Mechanic: Juan Crespo, ASE Certified Technician replied 1 year ago

Looking forward to reading something like "I found it!!!" from you tomorrow.

Best Regards.

Ask Your Own Jeep Question
Customer reply replied 1 year ago
Sorry for the delay. Last week got busy, back at it today! I'll let you know.
Customer reply replied 1 year ago
Took a peek around the exhaust for any burned wires, no luck. Peeled back the wire loom around the exhaust manifold in hopes of finding something around that. But the wires in that particular area look ok. What should I go after next?
Jeep Mechanic: Juan Crespo, ASE Certified Technician replied 1 year ago

If you've checked all the wiring and connectors and found no opens or shorts, then the PCM must be the problem.

Ask Your Own Jeep Question
Customer reply replied 1 year ago
Is this vehicle able to have a used pcm installed? Could you send me a wiring schemitc of the oxygen sensors (California model). I've done a visual inspection but I'd like to check everything with a ohm meter.
Customer reply replied 1 year ago
What all wires should I check @ the pcm, can you give me wire color & cavity location for everything? I don't want to just throw an expensive pcm at this without actually seeing the issue being in the computer.
Jeep Mechanic: Juan Crespo, ASE Certified Technician replied 1 year ago

I don't quite understand what you're requesting; the circuit diagram I previously uploaded for you shows wire color, PCM connector and terminal numbers. For example, O2 sensor 2/1 signal goes to PCM connector C1 terminal 25 on a Tan/White wire. If that is not what you need, or if you need anything else in addition to that, please let me know and I'll try to get it for you.

Ask Your Own Jeep Question
Customer reply replied 1 year ago
I'd like to get the wiring schemitcs for all the other sensors that aren't reading correctly. Check the attached pictures from the first post, like oil pressure intake air temp, engine coolant, manifold pressure, etc. anything that's reading abnormal. What should the specs of these sensors be with ignition on, and what readings should I get on each wire for the sensor.
Jeep Mechanic: Juan Crespo, ASE Certified Technician replied 1 year ago

I can certainly get you all that information for an added fee. Please accept the Premium Service Offer and I'll get to work on it right away.

Ask Your Own Jeep Question
Jeep Mechanic: Juan Crespo, ASE Certified Technician replied 1 year ago

Since it looks you're not accepting my proposed service, I'll opt out so others may try to help you. Do not reply until another expert responds or the site will cycle the request back to me.

Ask Your Own Jeep Question
Ask Juan Crespo Your Own Question
Juan Crespo
Juan Crespo
Juan Crespo, ASE Certified Technician
Category: Jeep
Satisfied Customers: 1,529
1,529 Satisfied Customers
Experience: A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European

Juan Crespo 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:

Thank you so much for your answer. My initial estimate was $325; I got it done for $100 - part and labor.

Lynn B.Ormond Beach, FL

I was skeptical at first but thought I'd give it a try. I was pleasantly surprised. Your site actually is a quality service that I would recommend to others in a heartbeat.

StanSayre, PA

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

< Previous | Next >

Meet the Experts:

Chris

Chris

Shop Foreman

3,449 satisfied customers

Jeep Certified Master Tech

Mark

Mark

22 Year Factory trained technician

2,593 satisfied customers

Jeep factory training........25 years in the industry.

Dave

Dave

Jeep Master Tech

1,149 satisfied customers

Chrysler Triple Master, ASE master Tech AA degree in Auto.

moparfl

moparfl

ASE Certified Technician

1,130 satisfied customers

ASE Master Tech Chrysler Dodge Jeep Master Tech

Tim Mohr

Tim Mohr

ASE MASTER TECH

1,021 satisfied customers

30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL

Ron Z.

Ron Z.

- Jeep Tech -

629 satisfied customers

18+yrs experience. State Inspector & Jeep Diagnostics/Repair

jeepmopar76

jeepmopar76

Jeep/Chrysler Triple Master Tech

579 satisfied customers

32yr ASE Master Tech, 9yr Chrysler Master Tech, 19 yr Jeep Dealership service including AMC/Eagle

< Previous | Next >

Related Jeep Questions
I have a 2005 jeep wrangler, I removed the rear catalytic
I have a 2005 jeep wrangler, I removed the rear catalytic converter, when I start the jeep the engine races. Would removing the converter cause this? … read more
AMEDEE
AMEDEE
AUTOMOTIVE TECHNICIAN
Vocational, Technical or Trade Scho
9,105 satisfied customers
Code p0420. Runs fine, mileage may be down some. P0420
P0420 catalytic converter efficiency down 2007 compass … read more
eauto
eauto
self employed
High School or GED
74 satisfied customers
I get all kinds of codes on my reader for the check engine
i get all kinds of codes on my reader for the check engine lights sometimes its just the … read more
Chris
Chris
Shop Foreman
3,449 satisfied customers
Check engine light is perpetually on for years due to o2
check engine light is perpetually on for years due to o2 sensors needing replacing. I don't want to\he expense of changing them out. Today it flashed for the first time when it was cold. Codes read cy… read more
Joecamel90
Joecamel90
Technician
Associate Degree
24 satisfied customers
Another question, same jeep. I attached a pic wit 3 codes I
Another question, same jeep. I attached a pic wit 3 codes I have. Seems to me it doesn't have enough power. Could be one of the codes?… read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
I have a jeep 2011 rubicon showing p0430 bank 2 code my
I have a jeep 2011 rubicon showing p0430 bank 2 code my motor was replaced about six months ago the service engine light was on before the new motor was installed. when I am in park with the vehicle r… read more
fordguy4u
fordguy4u
Automotive Tech
Vocational, Technical or Trade Scho
70 satisfied customers
2016 jeep wrangler unlimited sahara check engine light solid
2016 jeep wrangler unlimited saharacheck engine light solid on for P0420No exhaust leaks and we already replaced the 02 sensor twicecode still comes back on after a day or two of driving… read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
My check engine light came on and now my 2012 Jeep Patriot
My check engine light came on and now my 2012 Jeep Patriot is idling high and losses acceleration.… read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
On a 2005 Jeep Wrangler 4.0l I first had a DTC P2098 and I
Hello, On a 2005 Jeep Wrangler 4.0l I first had a DTC P2098 and I just erased. One week later the check engine light came on with a different code P0153. What is the most common fix on both codes? Tha… read more
roy
roy
Associate Degree
3 satisfied customers
I replaced the spark plugs the coils and I still get
I replaced the spark plugs the coils and I still get culinder 4 misfire. I re-gaped the plug no improvement. I have clean operation until it reaches 2k rpm. What else can it be?… read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
Bog down under acceleration. replaced throttle sensor,
bog down under acceleration. replaced throttle sensor, complete turn up and replace fuel fitler. had fuel pump checked for pressure and it was fine. can't get over 45 mph … read more
Gunvir Singh
Gunvir Singh
1,817 satisfied customers
Had bank1 sensor2 downstream of catalytic converter replaced
HI, had bank1 sensor2 downstream of catalytic converter replaced 1week ago, now engine warning light is back on. Prior to replacing the sensor gas cap light came on intermediately, then went away. Cou… read more
Ron Z.
Ron Z.
- Jeep Tech -
Vocational, Technical or Trade Scho
629 satisfied customers
My brand new 2017 Jeep Cherokee Laredo Limited is bucking as
My brand new 2017 Jeep Cherokee Laredo Limited is bucking as I start driving...Then a Warning message appears on the dash..."Pull over the engine is going to shut down" ??? Why? and What potential dam… read more
mauricio
mauricio
Vocational, Technical or Trade Scho
372 satisfied customers
Replaced the catalytic converters (bolt on y pipe with 2
replaced the catalytic converters (bolt on y pipe with 2 cats) on 06' jeep liberty 3.7L about 2 weeks ago. Today, after driving about 3 miles the vehicle died while driving (noticed RPM's dropping rap… read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
I have a 2002 Jeep Liberty 3.7 ...it has lost all power it
I have a 2002 Jeep Liberty 3.7 ...it has lost all power it will start and idle but won't go past 1000 rpms in gear.. … read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
Just bought a 1990 jeep wrangler 2.5 engine for cheap with
just bought a 1990 jeep wrangler 2.5 engine for cheap with mechanical issues previous had it in a shop they were unable to find the problem , they replaced the computer, fuel injector, fuel pump, jeep… read more
sprinkles08
sprinkles08
Technician
High School or GED
11 satisfied customers
I have a 06 Jeep liberty with a and miss and the engine
I have a 06 Jeep liberty with a and miss and the engine light is flashing, also a bad rattle noise coming from the exhausts… read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
I am trying to replace a catalytic converter on a 2005 grand
I am trying to replace a catalytic converter on a 2005 grand Cherokee 4.7 L. I have it unbolted, 02 sensors off and the support bar unhooked but cannot seem to figure out how to remove it. Its as thou… read more
Ivan Alvarez
Ivan Alvarez
Lead technician
155 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