DesertRat828
Newbie
So a little history, I have a 1995 K1500 5.7L 4L60E 302.5k miles. I've had it for just over 5 years now.The motor has been amazing, never had a single problem out of it. The transmission(or transmissions to be honest. 5 of them but who's counting) are another story altogether, but that's not what I'm making this post about.
So last year towards the end of summer my truck started stumbling and misfiring when it warmed up. Generally as long as I pulled over and let it sit for a minute it would crank right back up and I could be on my way like nothing happened. Then winter came with the cooler weather and it went back to being its regular Old reliable self. Not a single hiccup all winter long. Now I live in Phoenix Arizona and it has started to warm up already this year. 2 days ago as I was driving down the road it started stumbling again and misfiring/backfiring. It got so bad that I was down to 15 miles per hour on the highway trying to find a safe place to pull over. Every time I would hit the gas pedal it did nothing. No power whatsoever.
After searching through the forums for these symptoms and the causes of them I started leaning towards my timing being out of whack probably due to the original distributor and ignition control module under the hood. So I purchased a new distributor and set of wires since those were pretty old. I installed them on the truck and I know I was on the right gear tooth because I had it on top dead center when I removed the original distributor. However I guess when I put the new one in I didn't have it turned to the right degree for the timing because when I went to fire it up all that happened was it cranked and cranked and cranked for about 30 seconds before it let out a huge backfire from the exhaust pipe that sounded like a gunshot.
Now here's the part that I wasn't expecting. When that backfire went off it blew the insides of my catalytic converter out the exhaust pipe. I now no longer think that the distributor or timing had anything to do with the issues going on with my truck. I'm leaning more towards a faulty oxygen sensor that was allowing too much fuel through the system causing excess unburned fuel in the exhaust causing the catalyst inside the converter to heat up. The reason I believe this is because the pieces that shot out were melted beyond belief. The issue I believe I was having was that my catalytic converter insides had all melted creating a restriction in the exhaust. Because now that that clog is out, my truck is running better than ever.
Granted I'll have to get a new catalytic converter and I'll probably replace the oxygen sensor in hopes of improving my fuel mileage (I get about 8-9mog)
I just wanted to share this finding so that anybody else who has a truck that is stumbling upon acceleration or in warmer weather can consider the idea that their catalytic converter may be plugged up. Personally I never even considered it because I was told the cat was hollowed out when I got it which clearly was not the case. I'll try to post pics of the melted catalyst when I get home later.
So last year towards the end of summer my truck started stumbling and misfiring when it warmed up. Generally as long as I pulled over and let it sit for a minute it would crank right back up and I could be on my way like nothing happened. Then winter came with the cooler weather and it went back to being its regular Old reliable self. Not a single hiccup all winter long. Now I live in Phoenix Arizona and it has started to warm up already this year. 2 days ago as I was driving down the road it started stumbling again and misfiring/backfiring. It got so bad that I was down to 15 miles per hour on the highway trying to find a safe place to pull over. Every time I would hit the gas pedal it did nothing. No power whatsoever.
After searching through the forums for these symptoms and the causes of them I started leaning towards my timing being out of whack probably due to the original distributor and ignition control module under the hood. So I purchased a new distributor and set of wires since those were pretty old. I installed them on the truck and I know I was on the right gear tooth because I had it on top dead center when I removed the original distributor. However I guess when I put the new one in I didn't have it turned to the right degree for the timing because when I went to fire it up all that happened was it cranked and cranked and cranked for about 30 seconds before it let out a huge backfire from the exhaust pipe that sounded like a gunshot.
Now here's the part that I wasn't expecting. When that backfire went off it blew the insides of my catalytic converter out the exhaust pipe. I now no longer think that the distributor or timing had anything to do with the issues going on with my truck. I'm leaning more towards a faulty oxygen sensor that was allowing too much fuel through the system causing excess unburned fuel in the exhaust causing the catalyst inside the converter to heat up. The reason I believe this is because the pieces that shot out were melted beyond belief. The issue I believe I was having was that my catalytic converter insides had all melted creating a restriction in the exhaust. Because now that that clog is out, my truck is running better than ever.
Granted I'll have to get a new catalytic converter and I'll probably replace the oxygen sensor in hopes of improving my fuel mileage (I get about 8-9mog)
I just wanted to share this finding so that anybody else who has a truck that is stumbling upon acceleration or in warmer weather can consider the idea that their catalytic converter may be plugged up. Personally I never even considered it because I was told the cat was hollowed out when I got it which clearly was not the case. I'll try to post pics of the melted catalyst when I get home later.
