Going down the freeway the jeep struggles to do 65-70 mph sometimes struggles to do 60. Not sure what’s going on. No codes besides o2 sensor. It used to do 80 with zero problem and now it can only do 70 if I don’t let it shift into OD

99 XJ Sport
4in lift
33s
4.0 auto
Stock motor, trans, axles

 

Exactly which code(s)????

 

Checked your airfilter?
And under your airfilter?

 

And some other things to check when the engine behaves 'restricted' (like deprived from either fuel or air)

adjust throttle cable
check fuelpressure
TPS output scale
clean TB
Compression tests (if all else fails)

I don't think you'll be able to go around some checking, cleaning and testing...

 

Floor mat under accelerator pedal? More noggin pokin'.

 

Plugged up cat from ignoring an O2 sensor code for too long?

 

P0132
P0138

 

I’m running no cat as of right now

 

If I give it just the slightest bit of throttle at 60 it down shifts to 3rd. If it shifts into OD it starts to slow down and then I have to give it more throttle so it will down shift

 

Fuel filter been changed in awhile or at all? Could still have good fuel pressure but insufficient flow.

Also, did this problem happen suddenly? Or has it been slowly getting worse over time?

 

It’s slowly started getting worse. In the last year I put about 14,000 miles on it. When I first started driving it. It ran perfectly fine. It progressively started running like crap. I changed the injectors and it’s ran like it used to for about two weeks.

 

Is there a chance I could be getting the start of catastrophic failure? It only has about 159,000 miles on it

 

Let's not jump to any drastic conclusions now. Have you checked anything? A basic tune-up? Air filter? Spark plugs/wires/distributor? Brakes dragging? Check the tire pressure? Girlfriend put on some weight?

 

I had a new-to-me car once that I couldn’t even get up to 55. Spark plugs were really worn out. New plugs and wires and ran great.

 

Full tune up has been done within the last 5000-10000 miles. I haven’t checked the filter yet it will be the next thing i do. How do i tell if the brakes are sticking. i’m going check my toe as well