Jump to content

Dropped Y pipe now have a misfire?


Recommended Posts

Hello all, I have an 04 Sierra 1500 with a 5.3. The other day I dropped the front pipe to replace the gasket between the drivers side manifold and the pipe. Before this, the truck ran well, no misfires except for the occasional P0300 that they're so famous for. After reinstalling the front pipe, the truck has started to misfire something awful. It has no power, and there seems to be an extremely excessive amount of liquid (not sure it's water) coming out of the tail pipe. I checked all the ignition wires to make sure I didn't pull any off, and they're all connected. I had scanned the truck, and came up with the same P0300 Random/Multiple cylinder misfire. My next thought was that I had damaged either the O2 sensor in front of the converter or the sensor harness, but I was told that the O2 sensor would not cause a misfire. I don't believe in coincidences, but I can't think of anything else that it might be.

I've replaced both the driver and passenger side exhaust manifolds and installed a dynomax cat back within the past 5k miles, and before now have not had an issue. I was hoping to bounce this off of you guys and see if you had any thoughts.

Link to comment
Share on other sites

Just to add, I was replacing an aftermarket gasket that was different than the OE style with a gasket that matched the OE style ring gasket. I pulled the negative battery terminal to reset the computers, and I'm hoping that it would relearn the crank sensor and I would be able to pick up the specific cylinder that's misfiring.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.



×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.