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Jake, Nissan Technician
Category: Nissan
Satisfied Customers: 3903
Experience:  Experienced collision repair technician, Pulaski Tech graduate and DSM hobbyist.
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04 Nissan Titan, idles fine, but when driving it lunges,

Customer Question

04 Nissan Titan, idles fine, but when driving it lunges, sputters...then last night it shook violently and would not increase speed until I pulled over and stopped. Then it just limped home. The code reads bank 2 too lean, but the mechanic says that it is too rich.
JA: How many miles are on the car? What size is the engine?
Customer: 113k 5.6
JA: Are you fixing your Titan yourself? What have you tried so far?
Customer: Normally I do. I replaced the MAF and it ran great for about a week, then started again.
JA: Anything else you want the mechanic to know before I connect you?
Customer: the mechanic seems to think I may have an exhaust leak that may be throwing things off.
Submitted: 7 months ago.
Category: Nissan
Expert:  Jake replied 7 months ago.

Hey there, thanks for the question.

did anything significant happen prior to this happening? like the truck sitting for an extended period of time or anything like that?

additionally, you said it drove great temporarily after replacing the MAF, was it an aftermarket MAF or Nissan part?

Lastly, do you own the code reader / scan tool you were using? and if so can you give me the STFT or ALPHA readings with the engine running warmed up?

Customer: replied 7 months ago.
The MAF is a Nissan part. I had taken to shop for them to read the codes, I don't own a code reader. They said it shows that Bank 2 is too lean however the truck is actually running too rich.
Expert:  Jake replied 7 months ago.

Well generally a MAF issue which show negative correction. This is not a lean indication, but a fuel correction meaning it's trying to lean out the bank because it's too rich.

The Nissan part carries a 1 year warranty so keep that in mind

My biggest concern here would be looking at the fuel corrections, this can really tell us if it is in fact the MAF causing the issues or if there may be an air leak or something else on one of the banks.

The reason i asked if the truck had been sitting is because sometimes we will see mice nests in the air box when a vehicle is not driven for extended periods. This will cause it to run real rich as the engine cannot get air.

Customer: replied 7 months ago.
it idles fine, no misses...but as soon as I put it in gear and add a little strain to spits and sputters. I do drive the truck a lot, so I wouldn't think the nest is an issue
Expert:  Jake replied 7 months ago.

excellent, yea nest won't be an issue on a vehicle not stored for a period.

I assume you ruled out anything like filling up with bad gas when it started or anything like that?

probably the best resource we would have at this point is getting those fuel trims themselves. You could also do fuel pressure test under load to see if it drops out on you, if so do a voltage check to make sure the pump is getting the proper voltage from the IPDM. These trucks rarely have cam sensor issues or anything of that nature to be honest. The majority of issues I see are related to the MAF, The IPDM, or the fuel pump.

Expert:  Jake replied 7 months ago.

If you need further assistance let me know.

If not, please be sure to leave a kind rating! thanks.