I installed an LCE ceramic header, new O2 sensor, high flow cat and 2.25 exhaust (standard, not high flow... I don't like noisy exhaust) about 8 months ago. The truck passed smog shortly before this. Since then, it has run very rich... I burn a lot of gas and have ton of soot around the tailpipe. It has fresh plugs, wires, rotors, and a valve adjustment...

I need this truck to pass smog to sell it and I'd like to actually move the header to my new truck, but not if it's going to do the same thing to my new truck (which runs perfectly). Any ideas? I did a search on LCE header and everyone else seems happy with theirs, which is why I chose that one.

 

Check to see if you have any leaks at the O2 sensor, if improperly installed you will get a rich condition such as the one you're experiencing.

 

Ah, makes sense... so any leak upstream of the sensor would cause that right?

So, it's nothing inherent about the design of the LCE header with the sensor so far down the collector.

 

What brand O2 sensor are you running? I've found that the LC headers require a sensor with a long tip on them to get into the exhaust stream. The Denso sensors seem to work the best, they have a tip about 50% longer than other brands I have tried.

 

what year is the truck / motor?

was the OEM 02 sensor in the exhaust manifold (early slant nose 22RE)?

Shouldnt be issues with the 02 sensor in the collector...

But the older LC headers had a "stand off" and it pulled the sensor "up" and kinda out of the flow. Dunno what the headers look like today (mine was from when Larry Carpenter owned the place)

 

I am using a Denso O2 sensor and it was new when I installed the header. The truck is an 86 EFI (the one I'd like to swap into is an 87 EFI). I don't remember whether the sensor was on the manifold or the down pipe... I think it was on the manifold but after the merge, so should be reading all 4 cylinders.

The leak makes sense. I'll check on that.