I had a ford ranger do this sort of thing. No codes, and a black tailpipe and awful gas mileage.

It turned out to be a bad catalytic converter....the honeycomb in the catalytic broke apart and turned sideways.... All the O2's were working correctly and telling the computer to dump more gas in. Just something else to consider.

 

Thanks, I will check that out as well. Stuff like this makes me insane...

 

Ok, did the smoke test with rag in tailpipe, no leaks.
Swapped in the new injectors. Fired right up, ran it about 10 miles. Seems to be running ok. Filled up with gas to check mileage in a few days.

No luck on swapping out the O2 sensors yet. I need to get to Sears and get a 22mm wrench. Lowes here goes from 21-23 with no 22mm. Ill do that tomorrow and get them swapped out.

Not sure how I am going to check the CC, but banging the exhaust around does not produce any rattles.

 

catalytic can be checked with an infra red thermometer. don't know what the temp should be but someone around here should know?

 

Dump some sea foam in that puppy as watch her smoke

 

I'm not an expert on the 4.0, but I have been in on a few engine rebuilds in my earlier years. I tend to agree with the train of thought that says that the engine hasn't seated completely yet. Depending on how the cylinders were honed, it could seat very quickly-or not. You say it's idling ok but is it making good power throughout the rest of the rev range?
I suppose if you wanted to settle the matter you could either get an oil analysis to see if you are getting ring material (CrMo)or cylinder (Fe)traces in your lube oil-or you could hacksaw your oil filter apart and see what's getting trapped. Seafoaming the engine is never a bad idea if you want to start with a known clean engine.
Swapping out the sensors will also get you back to a "known good" situation electronically.

Again-certainly NOT an expert with this engine. Just trying to rattle some neurons.

 

The motor has good power through all ranges and is very "zippy". I do have a test kit from blackstone and when my oil change is due and plan on sending that in to set a baseline.

I have seafoamed the intake through the brake vacuum line and also ran a can through my first 2 tanks of gas. Should I add it to the oil a few hundred miles before changing it? Wasn't sure if this was bad with a new motor or not.

Also, I did swap out the downstream O2 sensor today, but what is a good way to remove the upstream one? I went to sears and picked up a 22mm wrench today and who-ever the PO had install the one that is on there foo-barred the head on it and the 22mm wont grip it. Is a pipe wrench a good idea or do I stand the chance of muscling it it up and ruining the entire pipe?

 

Ok, I swapped out the downstream O2 sensor yesterday and havent had a chance to do the front but now I am throwing the code -
P0132 (M) 1/1 O2 Sensor Shorted To Voltage Oxygen sensor input voltage maintained above normal operating range.
Is this normal and will be taken care of by swapping out the upstream O2 sensor or is it something else?

 

Ok, front O2 sensor is permanently part of the exhaust. It won't budge and I have torn it up so it is now rounded off... lol.

Can a muffler shop usually cut that section out and install a section with an O2 sensor receptacle in it?

 

Anyone?

 

checking your catalytic converter with an infrared temp gun is easy, the cat is a catalyst and is creating a chemical conversion which creates heat. a healthy cat will have hotter exhaust coming out than going in. to test, point the gun at the pipe before the cat and then at the pipe after the cat, the reading should be higher for the back

as for the upstream O2, an exhaust shop will be able to remove that for you, they have the tools and the knowhow to deal with a stubborn rounded O2, happens more often than you think, let them deal with it at this point before the exhaust pipe actually does become damaged. it will come out.

the upstream O2 will not fix that code on the lower. a short is a bad wire, poor connection, or faulty part. Check to see if the wire is touching the exhaust pipe, it may have melted through causing the short. pull the connection and see any of the pins is bent and not plugging in properly. Is this a good quality O2 or the cheapest one you could find? Parts matter, a cheap part is cheap for a reason, when dealing with electronic components, and especially testing electronic components, a cheap part may cause more problems than you had originally. It's my understanding that chrysler products prefer to have chrysler parts. unlike a ford that can have a chunk of wood subbed in for a part. Go NTK or mopar for best results on O2 sensors, I bucked up for the chrysler one myself

 

I took it to a muffler shop this AM, they were able to get the old one out but the PO's mechanic that put it in jacked the threads and they were unable to get clearance enough to tap it so they just cut it out and welded a new one in. I had them check codes when all was done and it is not reporting the P0132 anymore.

As I stated earlier, I got the NTK O2 sensors.

Next question, should I reset the computer to have it relearn everything?

 

shouldn't have to reset anything, most vehicles 98' and newer are smart enough, unlike the chevy's of the early 90' s that had to relearn after filling the tank.

just finished my first tank of fuel after changing my O2 and I averaged 15.5 MPG.
Sigh, that makes me a sad panda. changing the coil on tuesday.
I did find out that when going 100km/h by the gps, I'm showing 106km/h in the odometer, so my distance traveled is 6% further than calculated.

 

Ok, I have replaced the following in an attempt to increase my gas mileage and clean up my exhaust.

Plugs - NGK (added dielectric grease to coil pack boots)
Injectors - Bosch Bosch Design III 4 hole.
O2 Sensors NTK up and downstream
IAC - BWD
MAP - BWD
Intake vacuum line elbow connections.
PCV Valve


Vehicle when under throttle runs WAY better, gas mileage has went from 10.96 MPG up to 13.75 in the first 100 miles (all city driving, no highway). As it adjusts over time it should, hopefully, improve a bit more.

Engine does seem to idle just a tad rough at operating temp and idle 700rpm and when in gear about 550 RPM.

I still need to get back to the muffler shop and have my muffler replaced (Lifetime warranty) as the baffles inside are loose and cause a rattling noise when stopped in gear.

 

My experience is that the first 100 hours of operation are critical-whether it's electronics, engines or whatever-those first hours are when the wear patterns get established and it's the period when things are the most likely to break.

I think your engine is going to continue to improve provided everything was done correctly. Once you get 1000 miles or so you should notice a difference. It'll be smoother, quieter, stronger.

It used to be that a certain amount of roughness on cylinder walls was desirable so the rings and cylinder walls would mate to each other but in modern times the trend is to mirror polish the walls with a tighter end gap on the rings-initial wear upon break in is less and the seal lasts longer. You used to have to run the engine for a certain amount of time at a certain rpm-now they tell you to just drive it the way you normally drive it-just don't abuse it. Change the oil after a couple of hundred miles and call it good. God, I'm getting old!

Keep us aware of your situation-it certainly seems to be improving. Best of luck!