nabtastic

Before I posted anything I scoured the forum for answers and have:

1) cleaned throttle body
2) cleaned IAC
3) new spark plugs
4) new CCV elbows - front and rear. Rear needs new hose (has hole in it) but has electrical tape on it currently. Not sure if that's good enough. will replace this weekend if it's in stock at the dealer.
5) Replaced upstream o2 today.. very short test drive but no positive change, possibly worse


Here's the story.. I bought the Jeep a few months ago and it had a vacuum leak between the battery and headlight as well as a leaking radiator. I tried JB welding the pin hole which turned out to be stupid. It built pressure and busted a massive hole while driving to work. After 2 rounds of over heat, cool down, refill radiator and go a few miles I got it to work, were I could park it. My radiator was expected to arrive there the next day anyway. Not smart, IK but I didn't have a choice.

Got the radiator/ coolant/ water pump /upper and lower hoses changed and started her up. Ran fine for about a mile then it started the (apparently common) rough idle. Since the valve cover gasket was leaking I replaced it along with the CCV front and rear elbows. No change. Cleaned the IAC and throttle body. No change. Changed the upstream o2 with NTK part 23151. No change. This happened an hour ago and I'm waiting for traffic to die down but driving around the parking lot wasn't an uplifting experience.

Getting around 10MPG and it's (obviously) running very rich. The only code I've gotten was P0171 - bank 1 lean. 1 day I got 2 more codes: p1195, p0306 but they went away after clearing codes never to return.. It's an inline 6 so I assume that means the whole system is lean. Since a failing o2 sensor will read lean, causing extra gas consumption, I assumed that would fix it. The o2 sensor I replaced was covered in suit, which isn't surprising considering how rich it was running. I blew cigar smoke all over the engine compartment and can't find a single vacuum leak.

Cat plugged? Exhaust manifold leak? Keep driving? Take it out back and shoot it?

137,000 miles basically. I've ran multiple cans of seafoam and 1 fuel injector cleaner. no change..

Thanks,

nabtastic

After changing my O2 sensor it still idles rough, but doesn't idle in the 500 range anymore - stays at 700 but chugs through it. If definitely smokes way more than before though. As in, before the new O2 I would only see smoke if I really stepped on the gas. Now, it's pretty much smoking like a Cambodian mobster (i.e. constantly). I can't tell the color of the smoke thanks to my tinted windows. There's no visual evidence of a coolant leak - though i am definitely worried about it. Transmission and engine oil don't appear to have any discoloration and the spark plugs just look black.

My money is on MAP. Ordered a PT Autohouse MAP88.

BlueRidgeMark

Well, first off, welcome to the forum!

And secondly, fantastic job of posting your issue clearly and completely. You didn't force us to wade through a bunch of irrelevant junk, or make us ask a bunch of basic questions. Really good job!

Okay, p1195 is the O2 heater, so I'd be looking in that direction. Did you check the fuse for it?

You can probably ignore the P0306. It's a misfire on cylinder 6, and of course running that rich you're going to get some misfires. Expect to see more.

Did you check your grounds? Grounds on these beasts are really important. Search on "grounds" and username CCKen for some excellent info.

Also see Cruiser54s mostly Renix tips. I know you have a 99, but his stuff is really good and will give some help on ground locations.

Oh, and expect some people to come along and offer you advice on how to get better mileage. The usual stuff, go easy on the gas pedal, etc.

SatiricalHen

Have you checked to see if the coolant level is dropping? Smoke after overheating could be cracked head or blown head gasket. Maybe you have a crack in your exhaust causing it to run rich. I had a crack in mine and it didn't throw a code till I put in new o2 sensors (shows how good the old ones worked). Mine ran Rich and a little rough. It's a common problem with these engines.

Turbo X_J

Fred/N0AZZ

If I might ask is the Jeep still stock as far as lift, tire size or any type of engine mods? Also is it now running within the proper heat range as far as temps go while driving (around 210*)?


When changing a lot of the sensors it pays to use OEM ones as they tend to last longer and work properly. The above posts are all good starters to look at.


BTW WELCOME to the forum!

BlueRidgeMark

See what I mean?

nabtastic

Thanks guys - I'm actually a fairly docileis driver in the Jeep. My Ninja is where I let loose ... can do 115 and still get 2-3x the mpg lol.

The Jeep is completely stock - except the washers on the hood hinge.

The cap and plugs have been changed by the previous owner at some point. Lady owned it for 14 years and it's been entirely between AZ and HI, and like everything that comes to "paradise" it slowly stops working..

Engine temp stays 195-210 depending on how hard traffic hits and if the trade winds are blowing. I haven't done a compression test or CO2 leak in the coolant. I"ve not noticed any of the signs via the coolant or dip sticks.

I drove it a little while last night and the p0171 code came back. I've been driving like this for 5 weeks probably and this has been the only code to come back more than once. The smoke only really showed up after changing the O2 sensor (before it was only when flooring it). I know the exhaust manifold gasket is original and the exposed parts are flaky...

BlueRidgeMark

It's either the O2 sensor circuit (sensor, heater, wiring) or a vacuum leak. I'm betting on the 02 sensor circuit.

Driving habits, cool operating temps, big tires and lifts don't give your symptoms. Ignore that talk.

CR-Snow

I had similar problems. Bank 2 lean, burning lots of gas. I had a pinch in a wire between 02 and computer. Only way to tell was to watch it on a live scanner.

I would definitely stop running the sea foam though. That stuff is really bad on the catalytic converters in our jeeps. If the running rich hasn't damaged your cat already, the sea foam will finish it off. After I fixed my O2 issue, I started getting cat codes. Good luck man. I'd throw it on a nice scanner as soon as possible.

nabtastic

Pulled my plugs again - about a week of driving on them. Looked like they born in a coal mine. Check the smoke now that it's daylight over here - definitely black. HG seems unlikely given that there is no visual evidence in coolant or oil, even the inside of valve cover was purely black.

I just bought a cheap scanner ($70) because the parts guys @autozone said there wasn't a difference between the $60 and the $300 one.. How were you able to find the pinched wire?

Dis cap and wires are covered in oil by what I assume was the valve cover leak. No noticed cracks but I can't imagine it's in the best of health.

Also - any chance this is caused by the cat? there's no sulfur smell..just the smell of burning all my money in the fuel tank..

BlueRidgeMark

It's not the cat. It's the O2 circuit, somewhere, or it's a vacuum leak. Bad connection, blown heater fuse, something there.

CR-Snow

I'm pretty sure the computer doesn't adjust anything for having cat out of efficiency.. It's just mad and throws a CEL. So Mark is right.

I took my jeep to a mechanic friend with a fancy snap on scanner. He was the one who noticed the problem. My cheap scanner reads live data, albeit with some lag, but if yours reads live data you can diagnose this way.

Watch the 02 sensor voltage readout. I think it reads somewhere around 5v and fluctuates based on a bunch of stuff. What my mechanic noticed was every once in a while, the voltage would drop to zero, then come back up. We watched it do this several times in about an hour. So we jiggled the wiring harness and sure enough, it would go dead for a split second. So he found the signal wire and spliced in new wire to the computer. Haven't had an 02 issue since. Btw, this was after replacing the coil rail, the exhaust manifold gasket, and two upstream O2 sensors (a Bosch then an NTK. Stick with the NTK.

Last thing, and this won't affect your lean/rich condition, but change your downstream O2 to an NTK unit as well. The downstream doesn't affect air/fuel but it does affect the computer. It reads cat efficiency by taking a reading from your upstream, then compares it to your post cat downstream to determine if your cat is within efficiency range. If one sensor is new and not sooted, and the other is all gunked up, this will affect its ability to get a proper reading. This is from experience. Hope you get it resolved. I know what a PITA it can be.

CR-Snow

For the heater circuit, just swap over one of the relays next to it to see if it fixes. But I think you said the heater circuit code went away?

Here's the link for the scanner I have. It reads live data. For some reason Amazon is out of stock. Also ignore the bad reviews about the software only being in Chinese. That issue has been resolved.

http://www.amazon.com/gp/aw/d/B00DAA5A5M?fp=1&pc_redir=T1

nabtastic

I don't know if the heater circuit works or not but the CEL never came back. I followed this advice https://www.cherokeeforum.com/f2/o2-...r-fuse-199920/ and replaced all of my mini fuses. Going to replace the regular size fuses too. None were blown but all look a bit corroded. Excessive smoking stopped immediately. Now only a little black smoke comes out when I throttle hard. Going to travel the O2 wire next.

ordered this bluetooth OBD2 since it was instock. I'll send my original scanner to my dad.
Downstream o2 on order. Cr-snow, I'm originally from Etown!

Fixing the vacuum leak on the rear CCV elbow today. Was gonna get on OEM replacement but Jeep wanted $73. splicing the hose with free vacuum line from O'Reilly instead. We'll see how this looks in a few hours!