exhaust smells like running rich but no codes?

[ahardb0dy]

My 94 PF the exhaust smells like the engine is running rich, I don't have any codes, would the O2 sensor cause this? I have no idea if it was ever replaced. Thanks

[Precise1]

It could. There is a post by k9sar that outlines the resistance range a while back and a very recent one by someone else talking about voltage output. The FSM should have the diagnostics in it.

 

When rich though? Air filter?? MAF wiring or dirty?? EGR valve issues??? A lot of possibilities unfortunately. I'd simply start checking the basics.

 

B

[ahardb0dy]

It could. There is a post by k9sar that outlines the resistance range a while back and a very recent one by someone else talking about voltage output. The FSM should have the diagnostics in it.

 

When rich though? Air filter?? MAF wiring or dirty?? EGR valve issues??? A lot of possibilities unfortunately. I'd simply start checking the basics.

 

B

 

thanks, I'll look in the FSM for checking the O2 sensor, air filter is the K&N cone filter, think I have a small air leak between the MAF sensor and the adapter I made I can hear it whistling, MAF I cleaned, EGR valve seems to be working correctly, engine runs perfectly, idles perfect doesn't go up and down at idle at all. Going to see if I can fix that air leak first and I'll report back, thanks again.

[ahardb0dy]

checked the O2 sensor using the ECM, mode 1, let the engine warm up and first I was getting no flashes, than right before I asked my buddy to step on the gas the green started to blink, per FSM what exactly does "closed loop" refer to??

[XSrcing]

Closed loop means the ECU is using the data from the oxygen sensor to adjust fuel mixture.

[ahardb0dy]

Closed loop means the ECU is using the data from the oxygen sensor to adjust fuel mixture.

 

 

So I guess it's working, thanks

[ahardb0dy]

had the truck running for about 5 minutes before to check air filter and I can really smell that it is running rich, and noticed quite a bit of water coming out of the exhaust, is the water normal?

[XSrcing]

It sounds like the coolant temp sensor to the ECU is reading that the engine is always cold.

 

Yes, water out of the tailpipe is normal when the car is running really rich.

[ahardb0dy]

It sounds like the coolant temp sensor to the ECU is reading that the engine is always cold.

 

Yes, water out of the tailpipe is normal when the car is running really rich.

 

I can test the sender, I have an extra one also, will give it a try tomorrow, thanks again