1995 Cherokee Country Auto, 150k miles

Got my exhaust manifold replaced yesterday by a mechanic. Car had no CEL prior. With the new manifold on I have a CEL and a rough idle. I picked it up from his house and he had no scan tool to check the light... took it down to auto zone but they couldn't read it either. My thinking is maybe he messed up the firing order.. help would be appreciated.

 

Couldn't have opposite sides of engine, he could have not replaced the gasket and now you have an intake leak.

 

x2..plugs are on the opposite sides of the motor...however he could have plugged an injector in wrong or one of your vac lines could be unplugged. or as stated, could have not seated correctly when it was put back on. however, i had the later problem when i reinstalled mine, and with the manifold not on right the engine revvs to an absurdly high rpm...check the injectors and the vac lines first...take a picture of your intake if you cant figure it out

 

Have you checked to make sure all the sensors on the throttle body are re-connected? The IAC, MAP and TPS are all on there and if not connected they could cause a rough idle and probably put on the CEL also.

 

I'm not at my house right now, but will take some nice photos when I get home. Same time this happened I had some dental work come out... nice day so far.

 

dont need scanner to get codes search key on key off code acess

 

intake leak, vaccum hoses? i would look for the obvious first and yea look up the key on code reading.

 

I do believe a 95 is batch fire, so an injector plugged in wrong probably wouldn't do it still.

 

New O2 sensor or re-used? Might just need to reset the computer, it may have adjusted for the leaky old exhaust.

 

first pull the CEL code. On a 95 you don't need a scanner to do this.

without starting the engine, do the following:
key "on" - key "off" - key "on" - key "off" - key "on"
watch the check engine light and count the flashes. They will be in series of 2 with pauses between each number / set of numbers (eg. 3-2 -- 5-5). The last code will always be 55.


secondly inspect that side of the engine manifold for any vacuum ports / electrical connectors that are empty/missing/broken (vacuum lines, MAP sensor, TPS, IAC). Also check the o2 sensor connector for damage / proper hookup.

 

Wish I had read this earlier.. I was 300 miles from home at my folks place and decided to run all over town looking for someone with a scanner. Finally found a shop that hooked it up. Code points to an 02 sensor cable being shorted out. Now how could this happen? I don't think it was a fluke.

My gas mileage dropped by half.. fun trip home cruising 55 the whole way...

 

Bad O2 sensr, or he may have pinched some wires some how, or the like.

 

New Bosch Upstream O2 sensor solved the problem. Now just have to finish putting on the rest of the exhaust next week..

Thanks for the responses guys, as always I learned a few things.

 

grad you got it fixed

 

Just tried the key on key off, if I'm reading it right it flashed:
1-2. 2-1. 5-5.

Does that sound right?