PO172, PO173, and PO334

[Drakeborg]

I have a 1994 GT, bored .30 over, E303, pulleys, 70mm MAF, 3.73 gears, K&N air filter kit. Not the greatest setup but it works(worked) for me.

Im getting all 3 of these codes(172, 173, 334) when I run my OBD1 code reader.

The issue i have is that the car seems to run fine, but here and there the CELO comes on and then it starts to stutter and run bad. The light doesnt stay on very long. When its doing this i rev it up and it seems to run fine again for a bit. It is an intermittent problem so far. My first thought was the MAF, but i ran it unplugged and the same issue come about, except the CELO is on all the time unplugged. Am I just overlooking the obvious issue of the EGR being bad? I check the vacuum lines and there doesnt seem to be any leaks.

Any ideas hit me up.

 

[toyman]

Have you cleared all the codes stored to ensure they are current and not something from months or years ago? As far as the CEL goes, whatever sensor triggered it will clear itself after a certain number of operating cycles if doesn't reoccur. Codes 172 & 173 are lean and rich O2 conditions on the right bank. I suspect a bad O2 sensor. All sensors have a finite life. O2's usually need replacing at about 60k miles.