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2003 chevy
18 Posts
Discussion Starter · #1 ·
:confused:I have a 2003 TB, V6 4WD with 108k miles. im getting a SES light whenver i start to drive on the freeway. i got the code checked, P0172. it says fuel trim bank one condition. the fuel system for bank 1 was too rich. probable causes are:
1. if bank one and two codes set together suspect the MAF sensor
2. O2 sensor
3. ignition misifre
4. fuel injectors
i've already replaced the O2 sensor and spark plugs. ive also added fuel injector cleaner into the system. the code went away for a while, but once i took the truck on the freeway past 65, the SES light came back. should i try replacing the MAF sensor now? I was also told that it could be the gas cap. I also read in another post that the thermostat might be effecting it as well. please any help. thanks.

Western Canada Chapter
6,411 Posts
The '03 Inline 6 does not have a mass air flow sensor. It has a manifold absolute pressure sensor. You won't get a bank two code because inline engines only have one bank.

Did you replace both O2 sensors or only one?

The misfire condition will cause the SES light to flash meaning to stop and shut it down before you melt the Cat. Does it flash or stay on steady?

Have you replaced your fuel filter in that 108,000 miles?

Any chance the fuel pump may be going out as I have read that it sometimes can be related.
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