Originally Posted by jmrec100

Read your past posts. Good stuff there. What year was yours. Mine is a '94 Jeep Cherokee, 2WD 4.0L Does not have the EGR but all the other things apply.
You relocated the MAT sensor? Relocated to where? Is that MAT or MAP sensor. Don't know what a MAT sensor is. I have a bunch of work to do. The vacuum lines are really suspect. I spliced in a Poly tube to the Gas canister because it was all cracked tubing. Probably need to replace that whole line and some others.

Originally Posted by jmrec100

I also posted the first smog numbers previous post.
Trying to add what is important and I was screwing up the post.

Riverside County. Approx 30 miles East of Los Angeles.
As far as smog numbers, first time reading

I will put in new plugs tonight.
Are the Autozone plugwires ok to use? I can get those tonight

Attachment 199341

Nox was high, HC was almost fail.
2nd pretest: (no print out , halted as soon as Nox skyrocketed)
showed NOx over 2000ppm with new Bosch O2 Sensor and the Sealed the Exhaust manifold with ceramic epoxy.
You may be right in the out gassing.

3rd Pretest: Put in original old O2 Sensor and a new Catalytic converter.
NOx lowered to less than 1100ppm.

Next trial to put in the New Bosch O2 Sensor I already have, New plugs, new wires. and re-run pretest. I will ask for full test and print out. Probably Tuesday.

Could there be a possible issue with MAP sensor? Or Throttle Body as I read somewhere?

Originally Posted by highmileage

MAT- manifold air temp, located in the upper right of my manifold. Moved it to the air box(this is not smog friendly but ups the power a little with some extra fuel). There is no MAP on our XJs'.
If you put your mind to it it can all be done on a Saturday don't fret. mines a 90.

Originally Posted by cruiser54

There is absolutely a MAP on our XJs. On yours, folloe the hose from the passenger side of the throttle body back to the center of the firewall.

Originally Posted by highmileage

MY bad Cruiser.... was tired and was supposed to type MAF

Originally Posted by cruiser54

I was wondering about that. LOL.

Originally Posted by highmileage

Yup... too many cars, too many parts. Why can't they all just find something that works and stick with it.

Originally Posted by cruiser54

Because everything would be Renix.......

Originally Posted by jmrec100

Back at my Jeep. Had to put it off. Need to get it smogged. Last left this was a new cat and knocked the NOx to half but still high. Today putting in new NGK plugs and New Spark Plug Wires. The spark plug gap is supposed to be .035"> The plugs I took out were unbelievable. Must have been very old Autolite becuase the gap was at least .091".
Would this cause me some of the smog headaches? High HC but below max (barely). And would it affect NOx? Due to cylinder temps etc?
Next is to go do another smog pretest but get a complete read-out so can analyze it. Been doing partial pretest because NOx so unbelievably high. Doing everything up to but not yet new Exhaust manifold. Waiting for last resort.

Originally Posted by jmrec100

Brand new. I just replaced it. So why didn't I check the rest? A little bit lazy and a little recovery from a bad hand injury just made pulling wrenches annoying. But doing it. I want my jeep running. I read later after I bought and installed the rotor/cap that the brass work better. I'll get to that if there is an issue and will change it anyway after smog results.
Thanks. I'll keep you posted with numbers from smog later this week.