2brosgixxer

I just got a cel and checked it...codes 0307 (closed loop something) and 0509 (nothing listed) came up. Every search I have done leads me to someone quoting the exact diagnostic in the 4th gen "what do do if check engine light" but that does not really explain to me what the problem is. I am thinking O2 for the 0307, but which one and the 0509 I have no idea. Help please. Not having any driveability issues but it just came on so not sure if mpg is suffering. So again, 0307 and 0509 equals what? Thanks.

DennisMik

iTrader: (2)

03 04 = P1148 O2 sensor bank 1 sensor 1 (firewall side)
05 09 = P0154 O2 sensor bank 2 sensor 1 (radiator side)

I don't know why you would have 2 O2 sensors die at the same time.

2brosgixxer

2 things...you typed 0304 but maybe u meant 0307???? And where did you find 0509 cause I couldnt find It. So looks like I need 2 o2 sensors then huh? Thanks dennis.

Edit: yup, I had no cel and was driving Home when it came on...checked the codes and got both those. I guess It's odd that they both came up at once huh?

DennisMik

iTrader: (2)

Yeah, I'm a bad typist and a worse proof reader. Sorry. 03 07 is P1148.

There are 2 charts in the EC section of the FSM starting on page 4. Both charts have the Pxxxx and what I call the blink code (the charts call it the ECM code). First chart is alphabetical, the second is is sorted by the Pxxxx code. There is no chart sorted by the blink code so you have to manually scan for it.

What might actually be a little easier is Pmohr's decoder.
http://boredmder.com/ecucodes/index.php

If you think you have a Pxxxx code that may be an O2 sensor, use the 5th gen chart that is in the "5th Gen General Information, Maintenance, and Common Issues" thread.

I don't feel that my knowledge is all that great on O2 sensors to say that you definitely need to replace the sensors, but that's what the codes you got are for.

2brosgixxer

I just punched in 0509 in that link and got nothing. Hopefully someone else will come along with a definitive answer for me before i sink money into 2 o2 sensors. Again, the cel came on and ended up having those codes. I drove about 15 miles and had no hesitation etc.

DennisMik

iTrader: (2)

Interesting. If you say you have a 1998 in that link, it comes up. I wonder if your car is a late production model and got the 98 ecu.

2brosgixxer

Production date was 11/96

2brosgixxer

apparently when I looked up from turning the Ecu screw, I caught the flashes mid flash so ultimately read the code wrong. Anyway, seems the right codes are 0903 and 0705 for the evap canister vent control valve which i already knew was sticking but hasnt thrown a code for quite a while. So Dennis, if someone else comes up with 0509 on their 97, tell em to reckeck their codes.