P0171
 

fix one thing now another...

so i got my car through isnpection and fix the catalyst deficency code with a magnaflow cat. i havent had a CEL for about 500miles and all my I/M sensors have checked so i know its not gonna just come back with the previous code. now just driving to my friends house last night the CEL comes on, ok i scan it and comes back with P0171, lean bank one but car is running fine.

just doing the bit of research online ive learned to check vacum lines for cracks, inspect MAF, change upstream o2s.

this is what has been done in past year as far as maintence and mods, k/n cold air (installed 4 months ago), new rear o2 (1 month isntalled), magnaflow highflow cat (1 month isntalled), new ac-delco factory spec plugs and wires (12months installed), pacesetter header (with an exhaust leak, installed 12 months). new oem fuel pump and filter (6 months). the car is a 02 camaro 3.8l with 98k miles. obviously checking vacum lines are easiest thing to do but what else should i look out for?

thanks for your help

What bank is the exhaust leak on? Could be sucking air in and causing your o2 to see more oxygen then itsould making it think its lean.

i know for sure it is leaking on the driver side where the EGR connects (i can see discoloration where exhaust gasses are coming out) but could also be leaking on passenger side as well, i cant really tell for sure. it has been leaking for a while now with no problems

Look into that first. Could be the k&n but I would assume that it would affect both banks if the maf was contaminated

i thought that could be the problem too, but i have had it installed for a while now with no problems, i even let the filter dry before installing so any excess oil from the factory wouldnt contaminate the system.

It could b this?
 

DRIVER,SIDE,02 SENSOR, HIS BADDDDDD????.....:nod:

You have an exhaust leak on the driver side upstream of your front o2? You found your problem. If its a small leak, the computer will compensate and compensate until it can no longer. Resetting the computer or disconnecting the battery will bring you back to factory fuel trims. I would correct the exhaust leak first before going any other direction.

CEL went off on my way to work :bertstare:

Check fuel pressure? Maybe a bad FPR?