Alvarezxj

I got an 87 xj and just put a 3inch lift and some 31" tires. It does fine around town but on the highway it seems to lag on power. Is my xj not have enough power or isn't xj not running to full potential. My first xj so any help would greatly be appreciated. Thanks in advance.

devildawg99

when was your last tune up done? air filter,plugs, wires cap and rotor? maybe and upstream o2 sensor. I got a 99' with a 4.5" lift and 31's and its not doggy at all.

DKDunn04

I was running 33s on stock gears, and didn't really have any problems unless I was in the mountains. Sounds liek you need a tune-up.

Alvarezxj

I did plugs and wires bout a month ago or so and just recently did cap and rotor air filter was also done

jeepxj19

What gears do u have?

Alvarezxj

Stock I believe they're 3.55's

00jeepXJ

I have a 00 with 31's. Do a good tune up. If you have an auto you should have 3.55 gears. With 31's and an auto it's going to be pretty doggy on the highway. My 00 with a manual ended up needing to be regeared to allow me to drive on the highway and have power.

Skunkape

x2,Stock 3.55s on 33s no issues.I did notice when I first put on the 33s but I just drive it like a Jeep now not a car.And I have a bunch of extra weight on mine

Alvarezxj

Ok so I'm thinking my xj needs some work ill have to hit the drawing board

Gee oh Dee

Try the o2 sensor. From one 87 guy with 31s to another...

ProudXjOwner

Some 4.10's couldn't hurt.

Alvarezxj

ok not alot of funds but how much do 4.10s cost? and wat o2 sensor is there only one thats before the cat or is there more?

Alvarezxj

how much is it to get 4.10s? not a hole lot of funds. is there a sure fire way to tell if my o2 sensor is bad?

jeepxj19

If u had a bad o2 sensor u would be throwing a code, I believe there are 4 or 5 o2 sensors. To regear its gonna cost u some $$, itd be cheaper to swap axles.

Gorillaxj

regear would be nice but its a lot of money to do for 31's lol

i would also second the 02 sensor being a good place to start. you want to repalce bank 1 sensor 1 02 sensor. it is located right below #13 in this piuc. the single bung before the pipe ends.



I had 31's on my 86 with the crappy 2.8L and it wasn't bad with stock gearing. when my 2000 had 31's it wasn't bad at all.

02 sensors will throw a code in newer cars for sure. but in older ones (95 and older) the computers self check is not a strict and a slow or unresponsive sensore within its min-max range could not throw a code. if you have done the tune up stuff (i would do wires too) was done then I would do the 02 sensor.