I am at the point I really don't know what to do! A little background is I have a 2000 Discovery with 114,000 miles. It overheated due to a bad water pump. It dropped an exhaust valve seat and blew the head gaskets. No cracks to the block or heads. I tore the engine down and had a complete valve job done & exh valve and seat replaced. Replaced hoses, belts, plugs wires, cleaned throttle body, intake ect. Put it all back together.Due to the blown head gaskets it had crapped up the exhaust system & catalytic converters. I replaced the entire "Y" pipe with both cats and also replaced all 4 O2 sensors. I started it up and it ran smooth, but not for long, I once again had the "service engine soon" light & engine codes for misfire on all cylinders (P0300 thru P0308 and P1300 for multiple misfire). I took it around the neighborhood to check for exhaust leaks and when I pulled in the yard the right (passenger side) catalytic converter was glowing cherry red. it's a wonder the vehicle didn't catch fire. I was so mad I don't think I would have put it out had it actually caught fire, but anyway at this point I am at a loss for where to look now. Could it be my injectors are crapped up?? I also dumped a can of seafoam into a full tank of gas. Any thoughts, suggestions?? I don't know where to look now?? Thanks folks!!

Matt B.

 

did you install the wires correctly and tightly. seen the same problem and the guy didn't install them on the truck properly.

 

You are dumping fuel, can't say from where. A normal misfire from #8 wouldn't cause the cats to over heat like that.
Seafoam wouldn't cause. I am not sure how mechanical you are or if you know the next steps to take, but I would start with pulling the plugs and see if it is just #8 dumping fuel like a bad injector or if all the plugs wet.

 

Thanks Mike,
I think you've nailed it. I think it's a stuck injector. I cleaned the dirt and grime off the outside of them before replacing the O-rings and installing them. I was using a can of parts cleaner with the plastic tube you can stick into the can nozzle. I didn't use due diligence not to direct the spray at the injector nozzle and may have blown some trash into one or more of the injectors. Those cans of parts cleaner can really put out some pressure. My bad. I've been playing all this thru my head about what I may have done wrong during the reassembly process. Raw fuel will DEFINITELY make the catalytic convertor burn red!! It got so hot that the carpet above the muffler started to melt just a little!! Yikes!! After checking the plugs I think I'll be pulling all the injectors and sending off for cleaning/testing. Thanks for all the input!!

Matt B.

 

Did that possibly damage that catt?

 

possibly, clear the codes and drive it and wait and see.

0420,0430 are bad cat codes .

 

I really hope it didn't damage the cats or the O2 sensors. I fully expected to see the pigtail wiring to the O2 sensors melted. they weren't. They didn't even look heat damaged which really surprised me. I am preparing to replace all the injectors and hope the problems clear with also no damage to the cat. I'll post the results that I find!

Matt B.