Fuel pressure issue/lean issue.

Haven’t been driving my Jeep much it’s been making some weird noises and it pops and bangs sometimes also some clicky noises. As well as my header glowing red. I swapped the header for all the other issues to still be there. the fuel pump in the vehicle is stock as far as I know not really sure. And the injectors were replaced like a year ago. Any ideas? Could be the check valve is failing?

fuel pressure bounces, and when I primed the fuel pump, it loses pressure.

Also wondering if the check valve is on the fuel pump when I order it and what fuel pump that I should get.

1998 4.0
https://imgur.com/a/gN9R67x

 

Different years have different setups. What year is it and are there any codes?

 

I put the year at the bottom. And no codes.

 

I see it now. Cat might be clogged if your header is glowing. Fuel check valve and regulator are built into the sending unit.

 

I know for a fact that the cat is not clogged because I just rebuilt the whole exhaust system. It’s definitely gotta be fuel related. What fuel pump would you buy?

 

Pretty sure the regulator comes on the top of most new replacement pump assemblies. Might be a good idea to verify that the pump is getting electrical signal like it should before replacement.

 

What brand O2 sensors did you buy?

 

Can you find a Bosch or Delphi one? OE is always best, but i dont know if theyre still available. Id buy the whole sending unit. Is the fuel filter new? have you dropped the tank to look for contamination? When did you fill the tank last?
Check everything for a vacuum leak too. that can cause a lean condition.

 

Just a comment that on late model XJs, the fuel pressure regulator is also the fuel filter (which is different than the strainer attached to the fuel pump inlet). If not replacing the entire fuel pump assembly, then the pump and regulator should be changed together.