CEL comes on then goes off

[LEADFOOT]

pulled these codes

KOEO
111
stored codes
172 ox sensor r
176 ox sensor l
542 Fuel pump open, bad ground or always on
543 Fuel pump monitor circuit shows no power

KOER
111

Point a newbie in the right direction... thanks guys

 

[SHO#7]

I would start out with making sure you have no vaccum leaks, and clean your MAF. If unmetered air gets into the engine after the MAF the O2 sensor will never read correctly. Likewise, if the MAF does not give the proper information, the 02 sensor will not relay the proper information either.

Is the code for a certian bank, does it mention terms like HO2B1S1 or ( Heater oxygen sensor bank one sensor one. ) Or is it a system to rich/lean code.

Dont worry about the fuel pump codes for now. They are not triggering the SES lamp.

Mike

 

[LEADFOOT]

this is what i looked up

172 (R,M) Oxygen sensor not switching - system is or was lean - Single, Right orr Rear HO2S - Fuel control
173 (R,M) Oxygen sensor not switching - system is or was rich - Single, Right orr Rear HO2S - Fuel control

 

[projectSHO89]

It's 172 and 176. No lean codes.

Check oil for fuel contamination. Check for excessive fuel pressure. Check for leaky injectors.

That code pair means the computer has leaned out the mixture but the sensors are still still showing too rich.

Steve

 

[ohfosho]

it is the O2 sensors that pop the SES light on and back off while driving.

 

[ohfosho]

actually funny thing! my car started doing this again today. i got a 336 and 337. dpfe/egr codes. i guess my egr valve is clogged...great more work that needs to be done.

 

[SASHO91]

I wouldnt rule the EGR valve just yet....

Check the lines that run from the DPFE/EGR to the canister... sometimes they get bent, cracked, or just leak...

 

[Best Sho]

Codes 172, 176, 177 How to Fix?

I got the codes 172, 176, 177
So what do I do to fix them?

Thank You!
Mike

 

[NoSlo]

O2 codes are almost always from the o2 sensors if you haven't done anything else to the engine recently, especially if the CE light is going on and off and the engine is surging. Replace them if you haven't recently and your car will be happy.

 

[projectSHO89]

Not so.

"Rich" codes are usually due to either excessive fuel pressure or leaky injectors.

"Lean" codes are usually due to vacuum leaks.

Either code may also be caused by the MAF sensor sending an incorrect signal to the PCM.

All need to be investigated. If you just swap out the O2 sensors, you run a significant risk of wasting your money.

Steve



Steve

 

[SHOZ123]

I had a fuel injector that would not deliver the fuel properly. The SES light would come on and off while driving. The best clue was one plug that was always white while the others looked normal.

 

[Best Sho]

Vaccum Leak & Fuel

Ok Steve
I've never done this before so...

1) How do I check for vaccum leak? Just listen, buy tools etc.

2) How do I find out if it excessive fuel pressure or leaky injectors?

Thanks Again!
Mike

 

[SeanMc]

It's 172 and 176. No lean codes.

Check oil for fuel contamination. Check for excessive fuel pressure. Check for leaky injectors.

That code pair means the computer has leaned out the mixture but the sensors are still still showing too rich.

Steve

I had those codes. Changed my fuel filter, and I no longer have them. It is 172 and 173 though, rich and lean on the same bank.