warthog

I saw a thread about this a couple days ago but didn't want to hijack.
i am only getting about 230-240 miles (highway miles) a tank and i am seeing black soot in the tail pipe. i am wondering if i am running to rich. i have heard that it could be the rear o2 sensor but i do not want to pay 75 bucks for a new one on a hunch. if i run it with the rear o2 sensor disco'd. will it run better? will it run good at all?

I have also heard and just recieved a pm about a leak down test. seems a little to in depth for my garage so i would like to rule some other things out.

Thanks

Cherokee 4.0

What year is the 02 sensor? I have one for a 94

4.3L XJ

The way they have all the engines tuned these days, they all have black soot in the tail pipe. Not like the good old days when we kept them grey. Mine has it and it was pronounced "very clean". The only real way to check it is to have a smog check station sniff the tail pipe. Mine did it for free.

yellow97XJ

had a 95 and a 96 and the were lucky to get 230+ MPG and my 97 gets about the same with a 6" and 33's and 4.10's the other two were stock? dont know if they changed somthing along with the body style in 97?

warthog

it is a 98, how much would you take for it?

ah didn't know that. i know i just sold an 03 tacoma and bought it brand new and don't remember it having the black soot. i just wanted to make sure it wasn't burning to much gas.

i am new to xj's and there are not to many around here so i was not sure what the adverage xj got per tank.



Thanks All

97XJMopar

I get 20+ MPG, normally around 22-24 in town and with my old 225-70-15's I was getting anywhere from 24-27 on the highway. And mine has black soot all in the tailpipe