RTSVET

Can the o2 sensors cause these codes 0172,0175?

I have cleaned the MAF and the KN air cleaner and put new plugs in the car and it didnt help getting ride of the codes even after i clear them out they always come back with the engine light coming on.

If it is the o2 sensors how do i test them to see which ones are bad are do i replace them all and be done with it?

this all started after i did the seafoam topend cleaner thur the pvc valve vac. line on the intake so could this caused the o2 sensors to go bad?

Thanks Randy

SpeedyZ

Not likely an O2 senor, but possible. Normally the PCM will detect a bad or weak O2 sensor and set different code. How long has it been since you did the Seafoam? Check the oil and be sure it don't have a lot of fuel in it. Before I worried too much about this code I would run at least two tanks of fuel through the car. Get it up to temp and drive it for at least an hour to cook out any Seafoam or fuel that may be in the crankcase. Good chance it will work itself out after you run it a bit.

If not an ODBII scan tool will be your friend to watch the fuel trims and O2 volts to see exactly what is going wrong.

BTW: If it is an O2 sensor only the front two are involved in fuel mixture. The rear two are only used by the PCM for diagnostic purposes and would not be involved with this code.

RonSS

172 and 175: BOTH banks rich so like Speedy says, no I don’t think we can blame the 02 sensors. What ever the problem is its common to both banks, not just one. If after your two tank drive you’re still getting the rich codes then it’s time to look at the data going into and out of the PCM. 172-175 indicates that the PCM has to pull more than 25% off the fuel trim to get the O2 sensors to say: “This is 14.7 to 1”

RTSVET

I have put almost 200 miles on the car since the seafoam was done we drove it last weekend and it seemed to run great but still throwed the codes 172,175. I just went out and started it up to back it out of the grarge and it is missing bad now and the exhaust smells real rich and bad like sulfur are rotton eggs and wont hardly run so i guess it is time to go to the dealer to find out what is wrong.

SpeedyZ

Have you run the car up to temp for at least an hour? 200 miles of short trips may not do it.

Problems seems to be too much fuel from somewhere. At least that is what the PCM and your nose seems to tell us. Pull your oil filler and see if is smells like fuel in there. I'm thinking when you Seafom'ed it a lot may have gotten pushed past the rings into the oil. I'm searching for things related to the Seafoam since that is when the problem started.

Other wise it sounds like you need to get an ODBII scanner on there to see what the O2 volts are doing. A wide band O2 in the pipe to compare what the PCM reads from the factory O2's would tell you exactly whats going on with the mixture.

RTSVET

The longest trip i have been on since the seafoam was about 1 hour 60 miles are so but never got a chance to open her up to much traffic around.

I have not done a oil change since i did the seafoam but i will do that tomorrow and see if that helps.

I will be trying to get it into the shop tomorow are monday and see if they can see what is wrong with it also i just want to thank you for all your help with this problem.

Randy

SpeedyZ

Let us know what you find

RTSVET

No problem

RTSVET

I finally got it fxed today it was the passanger side front O2 sensor (replaced both front O2 sensor)and #1 plug was bad (cracked) and the injector was leaking down so we replaced the injector O ring now the car runs great.