98 Trans Am - BONE STOCK Codes 0171 0174.. help
10-08-2013, 09:31 AM
#1
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98 Trans Am - BONE STOCK Codes 0171 0174.. help OK, so about 4 days ago I got a new/used Trans Am. 1998, 150k miles... completely BONE stock.. unmolested! Looks like the only thing done to this car was oil changes. Hard to find one of those these days.
I've been reading on the boards and on google searches about these codes. I know what they are for.. etc etc. But it seems most people have problems with these two codes coming up after some mods, and this car is as stock as stock can be. It has that special layer of greasy dust settled on the engine bay that looks like NOTHING has ever been cracked open or changed.
So my question is... if everything is very very stock.. where would I start first when attempting to diagnose these codes (obviously without dumping $$$ in parts at this trying to "guess" the problem) I would actually like to find the problem and fix it instead of fixing EVERYTHING that isn't broken.
Thx
- also.... the car runs great, no oddities... no loss of power, no bad idling, nothing whatsoever, runs like a champ.
I do have a bluetooth scanning tool with an android APP (Torque) that I can aid in my diagnosis.. however I left it in a relatives car after doing some work on it, and they live 3 hours away, so I won't be getting it back for a couple weeks.
I've been reading on the boards and on google searches about these codes. I know what they are for.. etc etc. But it seems most people have problems with these two codes coming up after some mods, and this car is as stock as stock can be. It has that special layer of greasy dust settled on the engine bay that looks like NOTHING has ever been cracked open or changed.
So my question is... if everything is very very stock.. where would I start first when attempting to diagnose these codes (obviously without dumping $$$ in parts at this trying to "guess" the problem) I would actually like to find the problem and fix it instead of fixing EVERYTHING that isn't broken.
Thx
- also.... the car runs great, no oddities... no loss of power, no bad idling, nothing whatsoever, runs like a champ.
I do have a bluetooth scanning tool with an android APP (Torque) that I can aid in my diagnosis.. however I left it in a relatives car after doing some work on it, and they live 3 hours away, so I won't be getting it back for a couple weeks.
10-08-2013, 10:34 AM
#2
i have a 98 camaro i just pulled up the tune i have a code 171 and 174 (maybe the 0 is silent lol) they are fuel trim system lean bank 1 and fuel trim system lean bank 2... might need a fuel pump/filter or some oxygen sensors.
10-08-2013, 11:42 AM
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Try cleaning your maf. I had this happen on my 2000 z28. Also vacuum leaks can cause this. Check your intake plumbing for leaks as well as pcv system. If that all checks out. Monitor the live data on your STFT. Spray csrb cleaner and if it goes way - you found your leak. Start with this.
10-08-2013, 12:52 PM
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A 15-year-old fuel filter wouldn't be helping any.
Might look at ENG SEN fuse since that runs the MAF
and the O2 sensors, either or which could trim you
into the weeds. Odd that no sensor codes show -
might check whether somebody killed those before
you got the car, or if sensors appear to be acting
right. You also want an idea whether these trim
codes pertain to just idle (indicating time to replace
the front O2s) or across the load map (indicating
MAF more likely). Below and above 2500 RPM on the
pedal, will both show you different trims than at idle -
which one says +25%?
Might look at ENG SEN fuse since that runs the MAF
and the O2 sensors, either or which could trim you
into the weeds. Odd that no sensor codes show -
might check whether somebody killed those before
you got the car, or if sensors appear to be acting
right. You also want an idea whether these trim
codes pertain to just idle (indicating time to replace
the front O2s) or across the load map (indicating
MAF more likely). Below and above 2500 RPM on the
pedal, will both show you different trims than at idle -
which one says +25%?
