I have made a couple of posts referencing this issues, but here is the quick recap
I was driving hope from off roading when my truck wouldn't rev past 3k. It almost felt like it was a transmission issue. I immediately though, it was clogged cats, but when I drove it the next day when cold it was fine, then as it got warmer it wouldn't rev past 4k, then 3.5k, then 3k (not in a linear fashion. So I thought, it cant be the cats because it would do that all the time. After that I started changing sensors, MAF, Cranks Position, Cam Position, o2 sensor, Temp sensors and more. Hell, I even tried a back up ECU i had. Consistently time and time again, after driving for about 20 mins it wouldn't rev past 3k.
Now, keep in mind this isn't my daily so i wasnt in a big rush.
Finally, I took it to an exhaust shop and they put a camera down the o2 sensor and did a pressure test confirming the cats where bad. Well I live in Colorado and now we need CARB compliant cats. So i got a set of cats from Rock Auto and a Head Gasket kit from PT. I also did new plugs and wires. Also, another drama was my VSS hadnt worked for years, but i fixed that during HG job.
So after working on the HG for almost two months. (again i wasnt in a rush, and could only work on it in small clips with the "help" of my kids) i got it back and running but the original condition still existed, except now I was getting miss fires. So i changed out the coils and the miss fires when away but still had the low Rev. Then by the gracious goodness of PT he sent me a really fancy Snap On scanner to borrow so I could read trending data. I got it all set up to read/log and headed out for a test drive. I drove for 45 mins and my Revs where only limited to 4250 (which I think is normal) and the truck is running great.
In conclusion, I think I did in fact have clogged cats and my coils where bad and the heat affected them over time. Once replaced i think the Adaptive values needed some time to reset.
I cant thank PT enough for his support through all this. Just the HG along was a big undertaking and was always there for random parts and stupid questions.
I was driving hope from off roading when my truck wouldn't rev past 3k. It almost felt like it was a transmission issue. I immediately though, it was clogged cats, but when I drove it the next day when cold it was fine, then as it got warmer it wouldn't rev past 4k, then 3.5k, then 3k (not in a linear fashion. So I thought, it cant be the cats because it would do that all the time. After that I started changing sensors, MAF, Cranks Position, Cam Position, o2 sensor, Temp sensors and more. Hell, I even tried a back up ECU i had. Consistently time and time again, after driving for about 20 mins it wouldn't rev past 3k.
Now, keep in mind this isn't my daily so i wasnt in a big rush.
Finally, I took it to an exhaust shop and they put a camera down the o2 sensor and did a pressure test confirming the cats where bad. Well I live in Colorado and now we need CARB compliant cats. So i got a set of cats from Rock Auto and a Head Gasket kit from PT. I also did new plugs and wires. Also, another drama was my VSS hadnt worked for years, but i fixed that during HG job.
So after working on the HG for almost two months. (again i wasnt in a rush, and could only work on it in small clips with the "help" of my kids) i got it back and running but the original condition still existed, except now I was getting miss fires. So i changed out the coils and the miss fires when away but still had the low Rev. Then by the gracious goodness of PT he sent me a really fancy Snap On scanner to borrow so I could read trending data. I got it all set up to read/log and headed out for a test drive. I drove for 45 mins and my Revs where only limited to 4250 (which I think is normal) and the truck is running great.
In conclusion, I think I did in fact have clogged cats and my coils where bad and the heat affected them over time. Once replaced i think the Adaptive values needed some time to reset.
I cant thank PT enough for his support through all this. Just the HG along was a big undertaking and was always there for random parts and stupid questions.
