I would also check and replace the fuel filter...its a choke point after all.

 

Read post #2 there “Scooter”!

 

Well good, one process eliminated...

 

I could've gotten bad fuel. I've thought about that, but haven't tested my fuel yet. I think I'll do that today. I got the fuel at a newly built Costco near my house and I know I selected 91 octane fuel, but it is possible that the fuel could be bad or there's E85 in there. The thing that made me question if it was the fuel is that I filled up three other cars there within a couple days and one of them is my wife's 2001 xjr, and it had no issues.

 

Costco doesn't carry E85 that I am aware of...that includes in Honolulu.

 

I bought a fuel analysis kit from Napa that tests if fuel has water in it and if the fuel has gone stale/bad. According to the results of the kit, my fuel is good. The kit doesn't tell me if I have gasoline or E85, but it does smell like gasoline, so I'm pretty sure it's not E85 since that has a different smell.

The Costcos here only have 87 and 91 octane. When I was stationed at Pearl Harbor a few years ago, there weren't any gas stations on Oahu that carried E85. I did did find a gas station in Kapolei that carried 100 octane for nearly $9 per gallon!

I did take the upstream O2 sensor out on the passenger side and started the engine, but had the same result still. Tomorrow, I'll get the driver's side O2 sensor removed and will briefly start the car so I can rule out that catalytic converter being bad as well.

 

Running the engine with the upstream 02 sensors removed won’t tell you much. You could however look down inside the cats with the sensors removed and see if the honeycomb appears ok. Ok, it’s more like a mesh screen shape rather than a honeycomb but you get the idea. If that looks ok, I think I would do a compression test next. Do you have the tools for that?

 

I wouldn't do anything til I ruled out the cats. My money is on them.

 

I thought that if you remove the upstream O2 sensors and the engine ran fine, that means the cats were bad? I'll get a tool to look inside them. I don't have the tools to do a compression test, but am planning on either buying or renting some tomorrow so I can do the compression test over the weekend.

Are there any specific tests for the cats you recommend? I was planning on removing the coolant reservoir so that I could get the driver's side O2 sensor removed to test that cat this weekend.

 

If you want to drop the CATS, then you may want to review this. Yes its an O2 tutorial, but I dropped the CATS and it was rather easy considering.
Even if you just knock the connection off the bottom, you can get a scope up it.

https://www.jaguarforums.com/forum/x...cement-195018/

 

It is the downstream O2 sensors that monitor condition of the CAT-s. The upstream ones only sense the amount of oxygen coming from the engine and control the mixture. They are not affected by the condition of the CAT-s. I don't think removing the sensors will provide any diagnosis, it will just cause CEL and fault codes.