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jpaug01, Nissan Technician
Category: Nissan
Satisfied Customers: 427
Experience:  15 years nissan,infiniti exp nissan and infiniti master tech,GTR certified ase master L1 certified
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Nissan Frontier: rough idle..warm)-Stalling at Idle-Black smoke..drove

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I have a Nissan Frontier, 2002, 4cyl.
I have:
-Intermittant rough idle (after warm)
-Stalling at Idle
-Black smoke while running and missing
(The above intermittant and usually after warm-up)
The car has been running great and just drove 350miles on Monday wi no problems. This started yesterday.

jpaug01 :

Hi my name is XXXXX XXXXX I can help, do you know what code was stored when ck engine light came back on? how many miles on truck?

Customer: replied 6 years ago.
No, and today the Mechanic said that no code was showing. 140K.
I agree with you that a good tune up always does some good but i have toagree with the mechanic it is something else. When the ck engine light was on did it flash or just come and stay on?
Customer: replied 6 years ago.
Came on and stayed on. Still on.
In my opinion I see a massair flow sensor failing or an injector poss dripping black smoke means running rich and is confirmed using a diagnostic scanner, if the ck engine light is on there should be acode stored
Customer: replied 6 years ago.
Would these cause the intermittant problem. The car starts fine, runs and idles ok then after a minute or so starts to stall and runs bad wi black smoke, having to shift to neutral at stops to keep rumming?

Yes it can due to it being an electrical part the mass air flow sensor along with the oxygen sensor are big players in adjusting the fuel mixture via the ecm
Customer: replied 6 years ago.
Yeah, the mechanic seemed to suggest that it might be a "computer problem".
But, you are suggesting that Injectors, or the sensors are the culprits?
My first impression would be the mass air flow sensor because nissan has hd issues with those the whole time I have worked with nissan/infiniti. The oxyegen sensor could be stuck reading lean causing the computer to drive rich The injectors are possibly the culprit although i conider it an unlikely chance. I would suggest paying for diag time prefferably at the dealer to pin down exactly what is going on. Ibelieve in the long run this will save you money!
Customer: replied 6 years ago.
OK. I'll go to Cerritos Nissan in the Morining. Can I get back to you with the results?
That would be fine i usaaly dont get on the competer until after 7pm eastern time. cerritos is in california?
Customer: replied 6 years ago.
Yes Cerritos Nisan, CA 90650. Should I hit 'Reply "again or "Accept" to get back to you?
reply should bring you right back into this conversation
Customer: replied 6 years ago.
Customer: replied 6 years ago.
Hey Man. When You are online, i went to the dealer today and they report:
-Clean EGR Port Code: P0402 EGR BPT Valve P0400EGR SYST
-REC Complete Throttle Bady Assy (I think this means replace Throttle Body Assembly)
Yes at work today I look up a few things and found the technical bulliten to clean the EGR ports what can happen is if say 2 ports are blocked the EGR flow will be into the other 2 cylinders causing a lean misfire, then the ECM trys to compensate by driving the mixture rich (black smoke) not sure why they want to cange the throttle body? what was thier reasoning for that?
Customer: replied 6 years ago.
I'm not sure. Do the codesI gave you indicate a sensor frailure in the Throttle Body? That semed to be what they were saying. If I can get away with just cleaning the ports that would be great.
The EGR codes dont have anything common to the trottle body that i am aware of if it was my truck i definatly would clean the EGR ports and see how the driveabilty is I like taking things one step at a time.I hope this chat has been helpful, is there anything else I can help with?
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