69z-28

well i drive my LT1 everyday and it has never given me problems. yesterday i got in it after school, and started it up and it was idling a little lower then normal. so i gave it a bit of gas just playing with it to see what happens and it starts almost like dying. now it wouldnt die but the RPMs were between 5-800 and it sounded like it had a hotcam or something. normally when its cold i could redline it with no problems, i never did but im just making a point that i could free rev it all i wanted and no problems. well i had to wait a few minutes for it to start running normal. the SES light came on so i immediately drove to the local autozone to have it scanned. by the time i got outa my school lot it was driving normal again, idling fine and no problems but still SES. anyways, the light was the O2 sensor and the guy there said that it only went off cause of the way it was running. well today it did slightly the same thing. it seems when its REALLY cold like this chicago weather it will do it, but after i drive it around and come back 2 hours later its normal again. so its pretty much only when it first starts up in extreme cold. it has never died while it was doing this but it seems like it wants to. other than that no other signs. car has a 160 stat and throttle body bypass done to it which has been crossing my mind. otherwise it has mods in sig which are general bolt ons. anythoughts? could be IAC or something simple like that to make it run like this?

Guest47904

If you had an IAC problem, you wouldn't get an O2 code.

Find out the exact code number.

Then look on the right inner fender and see where the small bundle of wires goes down under the engine. The bundle I'm refering to is tie-wrapped to the inner fender and has foil around it where it runs near the manifold.

If it's is still there, you will notice with Hooker headers that the wire bundle is extremely close to the headers. Then the wires are probably cooked inside.

That bundle has the O2 wires, the knock sensor wires and I believe (not sure) the starter engagement wire in it.

69z-28

i beleive it is P0135 or whatever, its the regular O2 bank whatever, i cant remember. the light came on a few weeks ago with the same code but there was no misbehaving of the car like now. would the IAC cause it to run like this?

all my wires are tucked away from my headers, and if it was a problem i think it would have occured sometime sooner seeing as ive had the header on a year now with no problems.

69z-28

well i pulled a few plugs out and it seems there is oil dripping on them a bit. the worst one by FAR was this on here, number 3 cylinder. the area around the plug hole was splattered with oil i beleive and the plug was as well.

would this mean bad valve seals, which are actually fouling out my plugs and causing it to run like it is? like i said, it seems to go away after driving a while, then continues acting up after sitting a while, like overnight. sound like valve seals to you guys?

Guest47904

Too hard to tell if the inside is seeing any oil. The outside of the plug however rules out the valve seals. More than likely valve covers to do that. Check the valve covers to see if they may have worked loose. I think they require about 9 or 10 ft/lbs. Were the wires oil fouled? If so change them.

69z-28

i think its shooting out past the plug. the wires are fine. i know for a fact its not the valve covers. its coming from inside the cylinder, look at the threads on the plug.

Guest47904

2 problems with your theory of coming from inside the cylinder. One is, in order to get the oil to the outside of the plug, it would have to be loose. If it were loose enough to blow outside the plug, you would have a misfire code and the SES would be lit. Not to mention it would run like crap and you would hear a shh shhh shhh sound that many think is a ticking sound. And the problem would NOT come and go.

Second, if it was doing that, it would smoke AND plug a cat if you still have any.

This all assumes you are telling us everything.

69z-28

alright i can understand your theory of the oil OUTSIDE the plug, because i beleive it was in fact tight when i pulled it, however that is a LOT of pressure in that cylinder so maybe it was pushing past somehow. the valve cover and under it, all around is completely dry.

i have no cats on the car and it is cold as ***** out right now so it always smokes when i start it, which is why i think i may have never noticed them begin to go bad because its been 40* or lower the last few months here.

one thing i should explain tho... i pulled the battery off and then reconnected it and light immediately went back on and the car ran like crap.

then, i pulled a few plugs like i mentioned earlier found this oil crap and threw all the plugs back in, in a different spot. immediately after doing this, i pulled the car out of my garage and it ran perfect from the start with no SES light at all. so im gonna see how it acts tomorrow morning on the first start.

69z-28

alright ive been searching a little throughout the site and had a few quick questions regarding the SES light i got.

it was P0135, Bank 1 Heated O2 circuit dealy, so basically its not heating up quick enough.
would this problem cause the car to run how it has been running when it first starts up? also, i drove through some good snow the last few days and i have LT's with O2 extensions. would anything related to this cause the malfunction im having with the car? is it possible the O2 heater mess up would make it misfire as bad as it is right in the begining? it makes sense because one the O2s actually get fully heated from the exhaust gas, the problem goes away. so O2 extension problem or O2 problem itself? like i said, same code a few weeks ago but no noticable difference in driving, hooked up a scanner, cleared the code and no problem until this a few days ago.

Guest47904

Don't try to second guess whether a DTC is responsible for your problem. Just go ahead and repair it.

Step 1 check the U/H fuse panel to see if the 20Amp fuse #10 is good.

Then if need be, probe the pink and black wires going to the O2 for the presence of 12 volts with key on.

As far as wondering whether it causes your problem or not. You will need to monitor when the problem goes away compared to when it goes into closed loop. Until the time it goes into closed loop, the PCM ignores the O2's.

So if it is not heated properly when it goes into closed loop, it could be giving it bad readings. The only way to truly know for sure is to monitor the O2 signal AND the fuel trims at the time it goes into closed loop. Then see if it takes some time after that for the readings to correct themselves and the engine runs smoother.

Sorry about your oil problem but if the plugs were tight there is no way it came out of the plug hole. You obviously have a leak somewhere else. I suggest an oil change and put in dye with it. Consider using High Mileage oil to seal leaks around seals at least once to see if it has an effect.

69z-28

hmmmm. well my school has a very advanced scanner, however im not sure how im gonna track down where the problem is coming from, if i dont know exactly what parameteres the engine is supposed to be in at what points in time.

Guest47904

The problem is in the heater circuit. As mentioned, check the presence of 12 volts to the O2 in question at the connctor. If it has 12 volts, it has to be the O2.

My own experience with the wires I mentioned took a year and half to cook the wires and caused all sorts of problems.

The scanner isn't needed, only suggested if you want to watch what's going on.

The "parameters" you know.