Strange code

[m_son]

Hi, I have a 1995 G20 in Canada that I got a week ago and the check engine light came on while driving it on day six. It only has 77,500 km on it. First I check through all the threads related to my problem to help narrow it down and learn about the self-diognosis computer. I found it and tried it to see what the code was. That's the problem. The code was 77. I printed the scans that Boingo refers to and the code pages don't list any code of 77. Anyone know what this means.

Help.......
Thanks

[NismoPC]

I believe the MIL code 77 is the O2 sensor. Generally, we would assume the code 33 to be that, but 33 is actually an EGR malfuntion on the G20 and

77: Rear oxygen sensor - "Check the rear oxygen sensor & circuit

This is the secondary o2 sensor located on the drivers side of the cat near the rear.

[m_son]

Thanks. Got a chance to ask a mechanic and that's what it was. All taken care of and I'm a happy G20 owner again.