Hi everyone, just picked up my first XJ! It's a 2001 Classic Silverstone Metallic, auto trans. Not totally new to Jeeps, my family has had Cherokees and Wranglers for years, but this is my first personally.

I bought the truck last night, drove it home 35 miles, no issues. The muffler is rotting away as well as the tailpipe. The downpipe and all cats look to be in fine shape. I fired the truck up this morning and I had a CEL. I pulled the codes and it shows one code, P0161 which I researched and found it to be bank 2, sensor 2 (bank 2 o2 heater circuit failure). Seems to be a fairly common problem, does anyone have experience with it being something other than replacing the o2 sensor? If so, thoughts?

Also, on cold start up it takes maybe 5-7 seconds to crank over, warm start isn't as bad but still takes a while, more than I expected. Alternator is brand new, battery looks fairly new, volt gauge reads 14v. Thoughts?

Thanks guys, I look forward to being an active member!

BTW, here's my other ride...hence the username :2thumbsup:

 

Very shiny, welcome to the site and congrats on the XJ!

For your O2S problems the other failures are blown fuses and destroyed witing. The O2S heaters get their power from the PDC by the passenger fender. Check there first. The wires for the sensors can also fall down and melt on the pipes, causing shorts, or sometimes rodents eat them up and just break things. At any rate the O2 sensors are only good for about 80k miles and get lazy before they throw a code, causing warm running and mileage issues.

As for starting, it sounds very much like a bad check valve on the fuel pump. Next time before starting it up, flip the key to ON repeatedly for a few seconds, like:

ON OFF ON OFF ON OFF START

We call this the Poor Man's Prime. It will run the pump and build pressure in the system. If it starts right up after that you've got a leak somewhere.

 

Thanks for the info! Yea, I'll be replacing back 2 sensor 2 (downstream) sensor because that's what I'm getting the code for, and replacing bank 1, sensor 1 (upstream) sensor because thats the one that's fried. I did find a bit of wiring that the casing had rubbed away so I'll be repairing all of that as well.

As for the hard start issue, it still doesn't really crank like it should after I prime it 3-4 times...it still takes a few seconds. Once it starts, if I shut it off, wait a few seconds, then fire it again, it starts right up. I checked for leaky fuel injectors but didn't see any evidence of fuel on the manifold which leads me to believe its one of the check valves. GREAT, I JUST dropped the tank in the mustang to upgrade the fuel system, what a ****ty job. OH well, guess I can't complain much for what I paid!

ALSO! If anyone has the HARNESS SIDE clip for an o2 sensor off a parts car or whatever, please PM me, I need one asap!

 

Nah leaking into the manifold and not shutting correctly. You'd have one spark plug looking (more) fouled