1996 Trouble Codes Don't Reset after Multiple Drive Cycles

[Fairbs]

I wanted to throw this out there if anyone else is having a similar problem...

Recently, I needed to go through DEQ and failed the first time with a cat sensor code. After going through a shop and having the cat replaced, I thought I was good to go, but the check engine light remained on. It is supposed to reset after a few drive cycles, but it didn't. I'd say I went about 50 miles and started the car around 10 times. I used a code reader to erase the codes and the check engine light hasn't come on since. And most importantly, I made it through DEQ.

I'm not sure what's going on here, but it seems like I had a similar problem the last time I had to go through DEQ. At that time, I ended up replacing both sensors to get it through.

I've read in a few other threads (various types of vehicles) where people have had problems with the codes resetting. Looks like they had to drive upwards of 600 miles.

http://www.automotiveforums.com/vbul....php?t=1049585

This doesn't make a whole lot of sense.

[Tech II]

After they replaced the cat, did the garage clear the code? They should have and they should have test drove the vehicle for you and then checked that all your flags had reset....if they didn't they only did half the job....

My guess is that they didn't clear the code or drive the car, because they shouldn't have returned it to you with the CE light on........you cleared the code with your reader....now comes the fun part....unless you drive the vehicle, under the precise drive cycle conditions, it may take a few drive cycles to reset those flags....

In my state, when you fail emissions, you must go to a garage to get it fixed......the garage has a form they have to fill out, stating what the code was, what the fix was, and that they cleared the code and it hadn't returned....then you go back to the original inspection station, with that form, and they do a retest....the retest is for free....if you decide to fix the vehicle yourself, and you go back for a retest, and you fail again, you will be charged again...