I have an '97 SE that's running a little rough. WOT and normal driving is fine, but it chugs a little if I let off the gas completely. Last week it was throwing codes 0304 (KS), 0503 (front o2), and 0902 (rear o2), so i cleaned and swapped the two front o2 sensors (to see if the front o2 code would change positions). I also cleaned the IACV, TB, and EGR, but they were in pretty good shape. So far the front o2 code has not come back, but 0304 and 0902 both did, right away. This car has had 0304 on and off for the entire 11 years that I've owned it without any issues, so I'm not too worried. I thought 0902 would not cause any problems? I'm going to clean the MAF next, any other ideas?

 

It prolly your IACV. U can try cleaning it and troubleshooting it.

Clean your MAF and your grounds as well.

 

0902 won't cause any problems, but replace it to get rid of the code. had to do it before on our i30.

 

Finally got back to this. I've cleaned the IACV, MAF, and grounds, and if anything the car is running worse now. Code 0503 (front o2) has stayed off so hopefully the cleaning worked, but now codes 0705 (EVAP) and 0903 (EVAP canister vent control valve) are on, in addition to 0304 (KS) and 0902 (rear heated o2) which are still on. Makes me think something is disconnected but I double-checked and can't find anything.

Any ideas? Does that code combination indicate anything?

Thanks

 

the vent valve on your canister is probably bad (0903). 0705, 0304 go along with that code. fix the valve (get one from a jy) and those should disappear. 0902 - get a new rear o2.