speed + service engine

[db710]

Sorry if this was covered before and feel free to link me to a previous topic. When I go over 70-75mph for a couple minutes in my 2002 Chevy Silverado 2500HD the service engine light flashes and remains flashing until I reduce my speed. After I reduce my speed, the indicator goes off after about 30 seconds. Everything seems smooth and no issues other than that, but it's happened multiple times. Any suggestions?

[txab]

check for stored codes to begin with.

[db710]

don't remember them off hand but it was something air/fuel ratio or MAF related

[gmtech4]

don't remember them off hand but it was something air/fuel ratio or MAF related

that doesnt help much

[db710]

Fair enough.. I'll see if I can find the codes or have them checked again and post them

[searay220]

I'm sure you will come up with a P0300 code random engine misfire. This could be caused by at least a dozen things. I'm trying to fiqure this one out myself. I have no misfire or running problems at all so my next step now that I have spent several hundred dollars on parts that hasn't fixed it is to have a crank relearn done.

[db710]

Haven't had a chance to get them read again yet... It's not too pressing since that's the only time the light comes on, but that's the scenario I want to avoid... Buying random parts etc..

[db710]

Actually, here they are... P0171 and P0174

[Duelin]

P0171 2002 CHEVROLET SILVERADO 2500 HD V8

Fuel Trim Lean- Bank 1
– The ECM has detected a lean air/fuel ratio

Probable Cause

Lean air fuel ratio
Lean air/fuel ratio caused by a MAF sensor concern
Low fuel pressure
Faulty oxygen sensor





P0174 2002 CHEVROLET SILVERADO 2500 HD V8

Fuel Trim Lean Condition Bank 2
– The ECM has detected that the bank 2 fuel trim values are greater than 25%

Probable Cause

Lean air fuel ratio
Lean air/fuel ratio caused by a MAF sensor concern
Low fuel pressure
Faulty oxygen sensor

[searay220]

MAF sensor very common problem. Thats one of the parts I replaced for my trouble that didn't fix it. I have a good used MAF if your interested.

[db710]

I'll keep that in mind, but I'll probably try to clean the MAF sensor first and see if that does anything for it. Doubt it's related to low fuel pressure...just had the fuel pump and filter replaced

[txab]

Have you checked for unmetered air leaks? Intake gaskets, etc....

 

You still need to check fuel pressure reading, new pump means nothing if it's faulty

[db710]

I have not