I'm throwing a cel 74 code....which is a misfire in cylinder 4.
I used to be getting cel 71 - 74...but I pulled the plugs and they were really black from running rich...so I cleaned them off and put them back. Now I've only got a cel 74. I looked at the plugs in cyl 4 and they look good. They're black toward the bottom, but not the top. I did, however, throw a cel 1 (02 sensor) code right before I got the cel 74. Could the cel 74 be because of a bad primary 02 sensor? If so, would it be possible to switch the primary with the secondary? Just to see if that makes a difference.

Thanks


[Modified by asianspeed, 10:50 AM 3/4/2003]

 

Go get you a new one. napa sells them.

 

you can swap the primary sensor for the secondary and see if that helps...

change out your plugs...what did you gap them at ?

 

I'll try switching the sensors tomorrow...and just run a downpipe at the same time. Might as well, since the 2nd 02 sensor wouldn't be doing anything anyway.

And the plugs are brand new. Only used about 1 hour. And they're gapped at .032.

Oh and I've also got a 1g dsm 02 sensor laying around. I wouldn't be able to use that, would I?

Thanks

 

Ok,

I just can't figure this out. I switched the 02 sensors...so it's not a bad 02 sensor. I also switched spark plugs cyl 3 with cyl 4. Just to see if I'd get a misfire in cyl 3. But it stayed with cyl 4.

I've got no idea what else it could be. Maybe a clogged fuel injector....???

Some more information about the misfire. When I first start up the car after resetting the ecu...it runs pretty smoothly. And then about 20 seconds later the engine starts shaking, due to the misfiring, and then the cel will come on.

Please help...this sucks.

 

Ok, now I've got even less of an idea what's going on. I started the car up, checked the distributor, it's good. Still misfiring. Turned the car off. Started it up again, misfiring. Started it up. No misfire. I'm resetting the ecu right now. And hopefully it won't happen again. But isn't that weird?

 

check the spark plug wire for cracked. That may be your problem.

 

I checked the connectivity of the plugs..and they're good. I also removed the plugs and grounded it and it was sparking...so the spark wasn't the problem. So it's got to be the injectors. What I don't understand is that it's only doing the misfire sometimes. And other times it's not. Most of the time it does..but what would cause it not to sometimes. Oh and when I say sometimes, I don't mean once a week, I mean 1 out of 5 starts, it idles fine.

Any ideas?