Surge, engine light flashing

[GunnerSchenck]

He just said he got it scanned today and it's not showing any codes. Because he cleared them by pulling the negative terminal. So no. And most of us know that's worse than a light that's staying on. Flashing=stop driving.

 

[tjkj2002]

GM seems to be make their information the most accessible all the way around.
Shoot I mean even when it comes down to collision repair information.. seems to be the only manufacturer that doesn't make you pay to know where to section what joints, where they use what foams, etc..
Just technician friendly.. I've had more luck when it comes to hyundais and Nissans than trying to finding ford info. Seems if you don't pay for access to their database, you've gotta hit or miss it yourself.
Even redoing the last maxima I did, you were able to find sectioning locations (even though I just went with the factory seams on the front rails) but the next thing I go to do, ford fiesta.. nope, hop to the payment boiii

That being said, about the o2 sensors, I completely understand what you're saying about the downstream sensors, but if an upstream sensor causes a rich condition.. you're saying all that extra unburnt fuel makes its way out the exhaust as pollution? That's the only thing I've ever read that you posted that I've found questionable.. I'm not saying you're wrong, as you're obviously plenty knowledgeable and experienced.. just defies a decent amount of experiences I've run into.
So just to clarify, you're saying in no way will a bad o2 sensor, regardless of up or downstream, will cause a condition that will eventually clog up a muffler, then mid cat, then cats? And from there cause sticking exhaust valves, etc..???

Only failed downstream O2's will not cause a condition to cause the cats to fail or be damaged,failed upstream will cause cat damage.

 

[TruckerKevin]

The check engine light has only ever been on 3 times since I bought this jeep.

Once about a week after I bought it. I had it scanned and it showed the 2nd bank passenger downstream 02 sensor. The guy at oreillys cleared it just to see if it was a fluke. Jeep ran good no problems.

It came back on about 4 days later, stayed on for a day and cleared itself.

A week went by with no problems. Then,,,, 2 days ago the jeep started surging, prompting me to make this post. It was then,,,,, at idle,,,,, that the check engine light came on and started flashing while the engine misfired badly. Scared the heck out of me,,, I promptly shut it off and I think I was distressed is why I cleared the battery lol. Once I cleared it up, engine light never came back thus far, but the surging remains.


I hope this isn't one of those aggravating random situations that I might never get to the bottom of.

Me thinks that the peeps who owned this jeep before had this dilemma, cleared the codes and pawned it off to me to get rid of their headache . since it is so random.

 

[GunnerSchenck]

Only failed downstream O2's will not cause a condition to cause the cats to fail or be damaged,failed upstream will cause cat damage.

Okay lol then I in no way disagree anymore. Pretty much exactly what I was describing in my first post. I'd just assumed by the fact that his condition was noticeable enough that I didn't say upstream, but rather assumed it must be. I agree that the downstream o2 won't cause a rich or lean condition, but rather is meant to monitor the efficiency of the fuel air ratio to bring it as close to stoichiometric as possible

 

[GunnerSchenck]

The check engine light has only ever been on 3 times since I bought this jeep.

Once about a week after I bought it. I had it scanned and it showed the 2nd bank passenger downstream 02 sensor. The guy at oreillys cleared it just to see if it was a fluke. Jeep ran good no problems.

It came back on about 4 days later, stayed on for a day and cleared itself.

A week went by with no problems. Then,,,, 2 days ago the jeep started surging, prompting me to make this post. It was then,,,,, at idle,,,,, that the check engine light came on and started flashing while the engine misfired badly. Scared the heck out of me,,, I promptly shut it off and I think I was distressed is why I cleared the battery lol. Once I cleared it up, engine light never came back thus far, but the surging remains.


I hope this isn't one of those aggravating random situations that I might never get to the bottom of.

Me thinks that the peeps who owned this jeep before had this dilemma, cleared the codes and pawned it off to me to get rid of their headache . since it is so random.

As someone else previously stated, that does sound a lot like a TPS issue, and often won't throw a code.

 

[fastcarsspeed]

I would lean toward the TPS being the problem. My 02 has a TPS going that will not always throw the code. I get a surge/sluggish feeling when it starts acting up and it will take a little bit before it throws a code. I have a new tps sitting there. Also I had a problem with 02 sensors and may have to look at replacing the cats next but I have 290k miles on mine.

 

[TruckerKevin]

I am thinking so also. Could I just settle for an auto zone tps, or do you guys think I should spring for a mopar? Has anyone had any luck with the cheap ones? I hate to spend a lot when I am kind of guessing and assuming

 

[TruckerKevin]

Also, just for informational purposes. An update to what I have done.

This morning I bought a can of throttle cleaner, and cleaned the hell out of my throttle body.

I also ran a bottle of berrymans chemtool in the gas tank, and ran a can of sea foam through the intake. (I am partial to berrymans, we used it in a shop to clean carbs when I was a young tune up mechanic and it worked wonders).

I also changed the plugs. I found the old ones to be champions and I hate those plugs. I won't even put one in my lawn mower. I replaced them with auto lights.

While this did not fix my surging, I noticed an immediate improvement in performance, especially during take off from a stop. I have what seems to be a LOT more power to take off with. And it seems to idle a bit better. So it was all money and time well spent!

 

[LibertyTC]

Mine was surging around 1650-1750 rpm. My TPS was worn out and had a...
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Also clean the IAC and port if you have not done so already.
Link: http://www.jeepkj.com/forum/f202/how-02-03-iac-removal-cleaning-59462/

 

[tjkj2002]

As someone else previously stated, that does sound a lot like a TPS issue, and often won't throw a code.

I would lean toward the TPS being the problem. My 02 has a TPS going that will not always throw the code. I get a surge/sluggish feeling when it starts acting up and it will take a little bit before it throws a code. I have a new tps sitting there. Also I had a problem with 02 sensors and may have to look at replacing the cats next but I have 290k miles on mine.

Being as the OP has a '07 KJ it does not have a TPS with a electronic throttle body.

To the OP.......................

Run the Champion plugs(434's only) or the specified NGK's on the emission sticker,by no means run any type of gimmick plug(pulstar or E3's) or any iridium/platinum plugs.

Also never use any type of chemical cleaner on your TB since it's plastic and those chemicals eat away the special coating on it.Use only hot/soapy water(dawn dish soap works best) and a soft bristle brush.Of course removing it 1st is the best way and never force the throttle plate unless you want to spend a couple hundreds bucks buying a new one.

 

[GunnerSchenck]

Oh okay, didn't realize he had drive by wire. Good info.. but seems to be a tad too late as hes already sprayed what sounds like a decent amount of carb cleaner through there.. I've always used ngk plugs and had success with them..except for the first time I put on plugs they were bosch platinum or iridium plugs and really wasn't a fan of them at all.

 

[TruckerKevin]

This explains why I could not find a tps online lol. So back to the drawing board. Should I just ride with my autolights for awhile?

crap

 

[GunnerSchenck]

Did you look at your throttle body when you were cleaning it to see if you have an IAC? If so, I'd clean inside of it with q-tips and clean off the sensor as best you can.. though if you don't have one, this tip won't help you much lol
I mean if you have autolites in there I suppose it's your choice to continue with them. But if you go to an Advance Auto I believe they're only like $2 and some change a piece here for the NGKs that your jeep will love you for installing. Personally I've always been against autolites though, but everyone has their own preference.
I know my 92 explorer wasn't big on running autolites but I did run them in my mustang for awhile with no problems.
But personally I wouldn't put them in my own jeep..

Just double checked online and they're 2.49 a piece here for the NGK v-powers..

 

[tjkj2002]

No IAC either for electronic throttle body.

 

[GunnerSchenck]

Pretty much my question, so thanks man. So if the only code he's thrown is for a downstream o2 sensor, what do you think could be causing his surging?

 

[TruckerKevin]

I think this is fixed

On my way to church this morning it was surging worse than ever. And behold, the check engine light came on. I stopped my Oreillys and ran the code, it showed #4 cylinder misfire,,,,,,, 4 times. I went ahead and bought a Borg Warner coil pack, it was only $26. I figured if it didn't fix it, I would keep it in the glove box as a spare.

I cleared the codes, installed the coil pack, and took it on a 45 mph drive (this was the magic speed where it cut the worst) and it seemed to have fixed it (knock on wood). I was expecting it to surge so much so that I thought it was,,,, at least felt that it was in my mind. But if it is, it's nothing like it was!!!!!!

So, a simple coil pack. I was fearful it was a valve going,,,, or one of those issues that I would chase and throw money at and never really get to the bottom of!

 

[GunnerSchenck]

Glad to hear you got your problem fixed!

 

[JasonJ]

And cylinder 4 is on Bank 2 ... imagine that.

When my uncle sized the engine in his 2003 Durango, 4.7L, I snagged all 8 coil packs from that beast... you never know..

So Kevin, you never posted what the actual DTC number was. Perhaps it wasn't the downstream O2, but the upstream O2 sensor reporting a rich condition, caused by the misfire on cylinder 4, dumping unburnt combustion gases into the exhaust.