Problem:
SES intermittently flashing(HOWEVER DOES NOT THROW A CODE!)
Tried solutions:
8 new plugs (NGK Tr5 V power plugs)
New Autolite 7mm wires
ACDelco coil pack
Story:
My SES light started flashing. I had it checked out and I have absolutely NO codes being thrown. I think the computer isn’t sophisticated enough to log the problem.
I had a rough idle, my whole engine was shaking at idle badly. I changed the plugs and wires with what I listed above. All the original tr55(Yes double 5) plugs looked nothing out of the ordinary, with exception to the second towards the rear of the bay on the passenger side which reeked of gasoline. Drove the car after replacing the plugs and wires and still had the Service engine light flashing(and the new tr5 plug in the same spot smelled like gas). Therefore I replaced the coil pack. The car now idles much smoother, sounds better, and runs better. However the service engine soon light still flashes every now and then!
No power loss at all. Seems to only trigger the SES light at light throttle.(Over 25mph)
if that light is on it’s logging a code or you have some sort of wiring issue. A scan tool hooked up to the car while running will log actual misfires and even tell you which cylinder is doing it, and graph it real time. Could possibly be a cam sensor on the way out even a crank sensor issue though these are not as common on stock.
O2 sensor’s? just throwing that out there i know the cats clog easily and were a problem which is why they were warrantied for 12 years 120,000miles so maybe something like that since you say power doesnt seem to have been lost.
I’m running pace setter long tubes, to an off road y pipe, to borla-mouth.
I have upgraded Bosch o2’s for the front ones, and my rear o2’s are deleted. I had Firehawk tune out everything and check out my car and there is absolutely no recorded logs of the misfire problem.
The signs point to something up with cly6 witch you noted of the plug. You said you changed the plugs, wires, and that coil and it still fouled the plug. Its a 98 witch have some more downfalls, it should have the perimeter bolt heads, so you have no coil brackets making this a little more difficult. But I suggest you swap the coil pack harness, from passenger/driver side. And see if the issue moves with the coil pack harness. If its still #6 and its a M6 car I’d check for a bent push rod on #6. But check them all. Tons of m6 cars have bent pushrod and there no sings at all.
And check the grounds, 3 on the rear of the heads, the 1 to the block form the harness near the starter wiring. Other form the block behind the alt. the the driver side frame rail under the underhood fuses. I’m not 100% sure on the 98s, one of them on a back of the heads is for coils.
Do you get spikes of 4* KR when you feel missfire on the light loads. Its a 98 they have the problem, of 4* false knock. It’s the knock sensors and the harness. Its a good upgrade to change them for 99+ ones. More so a camed car, but if you have a bend pushrod(s) it was have the same susceptible affect. I think the SES light flashes on a 98 car from that too, but mostly is is from a P0300 random/multi missfires.
I just see the light blinking. The plug never fouled either, and I haven’t pulled the plug I just put the coil pack on today. I’m gonna run it another day and see if it maybe finally threw a code. On the old plugs nothing led me to think that I’m running rich or lean all plugs seem in normal condition.
I’ll check the grounds but I don’t think they are the culprit. Maybe the harness, but I sincerely doubt the grounds are of any issue.
I’m lost to, you said the plug 2nd form the rear passanger side was soaked in gas, you changed it. same plug reeked of gas. But you just said you think “all plugs seem in normal condition” ? No offense you need to have somone that know more look at it, and see what it is and isn’t doing.
He’s saying it ran like ass so plugs/wires were done. still ran like ass. plugs checked. #6 fouled out. coil pack was changed due to non firing. Car seems better. Could def be a knock sensor. Was the motor ever cleaned off with water? people do it and don’t dry it properly and it can pool in the knock sensor, rusting it out and killing the sensor. This usually is accompanied by running like a bag of ass though. Thats what Studderin mean by 4* KR. 4 degrees of knock retard. AKA it’s pulling timing because it is detecting knock/ knock sensor circuit has a failure. Like i said in the first reply, it needs to be hooked up to a real scanner (tech2,modis,brick,genesis, even HP tuners) so these things can be monitored and evaluated while idling/ driving under load.
ya, what pat said. but I didn’t want to get into it that far yet, on the 97-98 LS1 knock sensor deal. lol
what are you using to scan it?
Its a 11 year old car with 93K miles and its getting driven in the winter, it could very well be a damaged ground wire. Don’t over look that. start at the basics and go from there.
Ya its had over the web, let use know after you check the things listed. If I saw the car I could find it out quickly. did the missfire codes get turned off?