2003 Chevrolet Rough Idle

[Augusta]

Just wondering if anyone can help me with this problem. My 2003 Chevrolet 5.3L pickup has a rough idle at times. If I shut it off for a few minutes and start it up, runs fine. I have had the bank 1 O2 sensor go off a few times, replaced it, still goes off once in awhile. Replaced spark plugs as well, no change. Any ideas? Thanks

[Jeremy airjer W]

I'm guessing the specific code was either a P0171 or P0174 (lean 02 bank one or bank 2)?

Do you ever have an extended crank after a hot soak?

There is a known issue with vacuum leaks from the plenum gaskets going bad on those. Generally you'll see both of the above codes when that happens.

[LMITOUT]

Does it start hard after sitting a while? Fuel pressure regulator?

[Augusta]

Does it start hard after sitting a while? Fuel pressure regulator?

Always starts great, no problem there, so I don't think it is the fuel pressure.

[Augusta]

I'm guessing the specific code was either a P0171 or P0174 (lean 02 bank one or bank 2)?

[Augusta]

Could it be the temp sensor?

[Jeremy airjer W]

Could it be the temp sensor?

[Augusta]

The pickup seems to be running rich when it acts up.

[Jeremy airjer W]

Are you sure you replaced the right 02 sensor?

[Augusta]

I am pretty sure. Bank 1 is under the drivers seat correct?

[Fisherman For a Lifetime]

Couple Q's:

How many miles?

Did you ever replace the plug wires yet?

Did you replace the O2 sensors with ones from GM or did you go with the "Universal" ones from Bosch, etc...??

I hope you didn't go with the Universal ones...

[Augusta]

Couple Q's:

How many miles? 108,000

Did you ever replace the plug wires yet? No

Did you replace the O2 sensors with ones from GM or did you go with the "Universal" ones from Bosch, etc...?? Replaced with a Bosch...it was doing same thing before I replaced it. New one made no difference

I hope you didn't go with the Universal ones...

[Fisherman For a Lifetime]

Ok. I have the same truck.

You may not want to, but put in OEM sensors, those are not good.

Replaced my wires BTW and it smoothened out the idle well. Give it a shot!

[Augusta]

I agree, I am going to try new spark plug wires....and I will buy AC Delco