2004 TJ, Chasing Check Engine Lights

amor88

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Apologies, new to the forum here. If this is posted in the incorrect area, just let me know & point me in the right direction! Looking for some help with a new to me Wrangler.

Have a 2004, 4.0 TJ automatic & recently received a 0132 (02 sensor, bank 1 sensor 1) check engine light. At the time of the light the Jeep ran like it had a misfire. I figured with the amount of miles (124K) I better give it a quick tune up so I replaced spark plugs with NGK 3459 & coil pack with Walker 9212040 (921-2040), cleaned the throttle body, installed TPS & MAP Sensor with Walkers (All from Rock Auto), cleared the code, ran & the 0132 light came back. I checked spark and all cylinders were receiving strong spark.

I moved onto the injectors. Checking the wiring behind the valve cover along with the connection plugs & didn't observe anything abnormal. I isolated one at a time by pulling the connection plugs & when I pulled injector #6 the engine didn't run any different. I didn't have a noid light at the time so I pulled all the injectors, tested individually by applying 12V & found #6 not cycling correctly. I cleaned them, blew them out and #6 now seemed fine so I re installed. Once started, there was an odd tick sound that was not there prior, along with the same 0132 engine light so I replaced all 6 with TRQ's off amazon. ($130.00 for the set). No more tick sound but still have the 0132 light along with same misfire / erratic idle. I purchased a noid test light and they all receive signal / flash as intended.

I was in town so I picked up an 02 sensor (Walker 350-34592), installed & the 0132 light went away. Ran it up and down the road & got another check engine light. This time 0175 (system too lean). WTF.... I checked everything over again, ran a fuel pressure test on the fuel rail and was getting 39psi with key on & 48psi with engine running. Turn the engine off & it held 48psi without issue....

Figured what the heck, cleared the lights again, ran up and down the road & it would up shift & downshift out of overdrive non stop and seemed more gutless then normal. (Assuming because its not happy & misfiring) either way, it threw a different engine light. This time 0152 (bank 2 sensor 1). I pulled over, cleared the light, flipped the over drive switch & oddly enough, ran further then I have before & it never threw an engine light.... I'm not sure if that's because its happier at high RPM? or what but im stuck here and needing some suggestions.

Am i missing anything here?
 
So do you have the ability to read live ODB data? Looking at the O2 voltages might help...and other PIDs.

Might want to check for intake and exhaust leaks.

-Mac
 
Update - After a leak down test & showing valve blowby, I Ended up pulling the engine & rebuilding everything just to have piece of mind.

Head needed decked 10 thousands & Re valved
Installed dew piston, rings & bearings
New Cam, Lifters & Push rods
New timing chain & gears
New Water Pump & thermostat
New Oil pump & all new gaskets

During the rebuild I did find some hidden gremlins so defiantly glad I did the full tear down. Long story short, Its all back together running & driving perfect.

Also, If anyone needs a rebuild kit, contact Clegg Engine Sales <sales@cleggengine.com>. Quick responses, good pricing & quality parts.

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Rocker arms were completely covered in sludge. I've never seen anything like it & recent oil changes showed no signs.

Head gasket didn't leak but defiantly showed signs of damage. Assuming previous owner did some work on and didn't clean the surfaces prior to installing new.

Timing chain cover didn't have a guide / chain tensioner. Chain was slapping against the cover.

Cylinders showed some wear but after a good honing, they cleaned up nice

Intake vacuum boots were pretty soft and falling apart

Random hardware missing or broken. Were able to extract them all and replace with new.

With the exhaust off i was able to clean up and patch where needed.

21 year old jeep that was due for a good servicing lol!