1-8-4-3-6-5-7-2
I'm Awesome
1997 C1500 4.3 auto
If I run the engine hard like merging onto an interstate the engine will start to miss out real bad like it's running on only 2 cylinders. Imagine putting the power on a light switch and flipping it on and off real fast, that's what it feels like. It's like the power is on-off-on-off-on and so on. I let off the gas and keep the pedal at a normal cruise speed and it bucks for about 20 to 30 seconds and then it clears up.
Plugs, wires, cap, rotor were replaced about 2 years ago with all AC Delco stuff. (plug wires may have been another brand, but still decent. I don't buy crap wires lol)
Checked the fuel pressure a year or two ago when this problem started and it was a couple pounds under spec but that could be my cheap gauge not being accurate.
Now on a cold start I can hear a horrible loud rattle noise coming from the catalytic converter area. I don't think it's the transmission making the noise, but it's hard to tell for sure. After the engine warms up the noise gets much quieter and is only heard at a certain RPM when beginning to accelerate.
Codes are p0147 (rear o2 heater circuit) and p0304 (cylinder 4 misfire)
Based on that info, what are the chances I have a bad catalytic converter?
If the cat is bad, anybody know if there is an off-road y-pipe available for the 4.3 Vortec? I used one years ago on my 96 Burb 5.7 but can't find one for this truck.
If I run the engine hard like merging onto an interstate the engine will start to miss out real bad like it's running on only 2 cylinders. Imagine putting the power on a light switch and flipping it on and off real fast, that's what it feels like. It's like the power is on-off-on-off-on and so on. I let off the gas and keep the pedal at a normal cruise speed and it bucks for about 20 to 30 seconds and then it clears up.
Plugs, wires, cap, rotor were replaced about 2 years ago with all AC Delco stuff. (plug wires may have been another brand, but still decent. I don't buy crap wires lol)
Checked the fuel pressure a year or two ago when this problem started and it was a couple pounds under spec but that could be my cheap gauge not being accurate.
Now on a cold start I can hear a horrible loud rattle noise coming from the catalytic converter area. I don't think it's the transmission making the noise, but it's hard to tell for sure. After the engine warms up the noise gets much quieter and is only heard at a certain RPM when beginning to accelerate.
Codes are p0147 (rear o2 heater circuit) and p0304 (cylinder 4 misfire)
Based on that info, what are the chances I have a bad catalytic converter?
If the cat is bad, anybody know if there is an off-road y-pipe available for the 4.3 Vortec? I used one years ago on my 96 Burb 5.7 but can't find one for this truck.