Well I've searched and searched for the cause and I can't find it. I spelled it out (one) in the topic so people can search in the future in case anyone is wondering, because searching for "code 1" yields nothing useful since 1 isn't indexed. Here's the situation.

With both a PG7, PM6, and PM7 ecu I get a code 1 CEL, usually after about 1/2 hour of freeway driving. I've changed the sensor and that didn't fix the problem. Could this be related to the gas cap as it is on newer cars? Inside my teg's gas door it tells me that if I don't hear three clicks when I tighten the cap I can get a CEL, and I think my civic has an 81 Civic's gas cap on it (don't ask). The only other thing I can think of is maybe my cheap autometer a/f gauge is dropping voltage quite a bit maybe, but I have it tapped right at the sensor so the voltage should be pretty equal at the ECU and at the gauge.

I know other people have this problem because I've seen it posted before but I've never seen an answer that really satisfied the issue. Anyone?

 

I have the exact same problem! I drive from Downey to Hollywood everyday. Its exactely 30 miles. Usually light turns on 2 or 3 exits before i get off.

 

Yup, my drive is about the same length and happens about 2/3 into the drive, maybe a little later. Do you have an a/f gauge? Have you changed out your o2 sensor since it happened?

 

so basicly you need a new o2 censor...... rite?

 

No bro like I said in my first post that I changed the sensor and it did not rectify the problem. Please nobody pm or email me trying to sell me their old sensors.

 

did you reset your ecu?

 

Yea and like I said I tried three different ecus so even if I didn't reset them they would have reset when I pulled one out to try the others.

edit: and yes I know they have to be disconnected for a bit to reset, I chip and edit my own ECUs using turboedit.

 

i've got the same problem and i'm not sure what to do about it, so if anyone knows the answer could ya share it. anyways lets keep this post up until an answer is resolved. thanks

 

have you checked your distributor for making interference to the oxygen sensor signal???? One way to check is place a radar detector right up to the windshield and see if it reacts.

 

Yea let's keep it going until it's fixed. A good way to get this figured out better would be to list off what you've tried. For example I'm going to try disconnecting my a/f meter. I have tried a new o2 sensor. I have also checked for vacuum leaks using the old shadetree method of spraying a bit of starting fluid around the engine compartment while its running to see if it revs up ever. Nothing.

 

Have you checked the actual wiring for the sensor to make sure it hasn't corroded through / covered in gunk? BTW, I'm having the same problem, just not as often. More randomly.

 

We get it once and awhilewhen we convert the OBD-0 cars to OBD-1. Not sure either what causes it but if anyone knows, please post it.

 

did anyone find a solution to this problem, i too am running Turbo edit and see the same thing

 

I've replaced:

O2 sensor
Fuel injectors
Fuel Pressure Regulator

Still get the same damn CEL

Anyone swapped their fuel pump ?

 

maybe it is the wiring harness it self? this problem sucks

 

Ha, I have the same problem! CEL doesn't come for a while, then bam, like a sore thumb it throws the code

 

Usually the computer will give the cel after its seen the problem more than once and for a certain amount of time. I would disconnect the A/F meter and then back probe the o2 wire with a meter or a scope and watch the cross count pattern, voltage, and speed. Also check the wire for a short to ground or power... although its probably not to power unless 3 computers were bad... let me know what you come up with. P.s. new parts are known to be bad, i see it every day.