I will only side track this thread for a second before a mod says something. Have you had your icm tested? This is usually what happens when Ignition Control Module goes bad.

To be honest I was in the same boat, hoping that the cat wasn't the problem. I went through the steps of a routine tune up, plugs - cyl 4 and 6 were a little moist but not to bad, wires, rotor button and cap. All helped but didn't cure the problem. Then I saw a couple of threads about the problems a worn gear on the distrubitor would cause so i pulled that out and decided to replace it. The gear was worn but did not solve the problem.

I noticed a gas smell after filling the tank one day so i popped the top so to speak and cylinder 1,3,5 and six of the intake had some definite wash action going on. I had replaced the fpr about 8 months earlier so I decided to take the dive and replace the whole spider to the updated mfi.

To help shorten the story I tested and cleaned every sensor I could find. The only things not replaced were the maf, iac and three of the o2 sensor. Mind you I didn't replace stuff that this site said were with in specs which happened to be those few things.

That is why money was so short for me by the time I actually got down to the cat and on down through the exhaust. Do I feel bad I spent all that? No, because it was bad anyway. I have actually spent far more keeping it running than I paid for the thing in the first place but I love the old thing.

Basically what I'm saying is it could be one of dozens of things causing the problem. I'm pretty sure that most of what I replaced caused in part the cat to go but who knows for sure.

 

I really appreciate the insightful story and that you keep coming back to add input. Tomorrows suppose to be a nice sunny 50 degree day so ill be doing some work or at least try

 

That's why this forum exists. I understand about the temps though. Mine all happened during a week where my area of Fl was in the low 30's all week. My blazer is the only vehicle I have though so I had no choice but to work on it. But, I don't mind the cold either so that helped. To bad you are in Oh or I would offer to help you run through everything.

 

Any update on where you're at with this?

 

no it just started getting warm so i pulled my cbr out hahaha, but ill be looking at it tomorrow most likely.

 

For the miss fire code you might want to check the spider injector (fuel injectors). I had a 99 s10 4.3v6 that i replaced the spider injector with an aftermarket one. After about 80,000 miles i got a random missfire code and it drove me nuts cause at first it would just act up for a few miles like twice a month but after 6 months it got worse and the truck acted up constantly with lots of smoke out exhaust, all unburned fuel. Took to pro mech and told me that spider injector was bad on cylinder 5. Since i do most repairs myself i payed pro mech $60 for diagnosis and checked out injector myself. Found that #5 injector wire had rubbed on lower intake and actually was shorting out and constantly spraying fuel into #5 causing the misfire and constant smoke of unburned fuel. Spent the extra $ and bought new ACDelco spider injector. They reason i replaced the original spider inj. was fuel was leaking on top where the wire harness plugs in. Just another reason to spend the extra for OEM parts. Hope this helps.

 

I'm not sure if mine has the spyder injectors, I don't think I do but I'll check that out. I went to get plates yesterday so I needed an E-check (ohio), I tried to clear the code before i went in to make it pass but it didnt work so I said go do the smoke test and it actually passed. I was kind of shocked.

 

Today is a good day! my problem was that the camshaft positioning sensor was disconnected. Idk how it happened but my problem is fixed and i didnt have to pay any money, wish i woulda looked at that sooner lol thanks for everyones help!

 

Glad it was something so simple!