Yet Another Idle or mis-fire prob

[bboypowerhouse3k]

i owned my G for about 3 years now and my first year into owning it i started moddin it
did my exhaust and from that my ses light came on.
aside from that i changed the oxygen sensor near my cat using a universal one.
well to sum it all up a few days ago i noticed my car started idling funny and actually stalling every time i stopped at red light
i tried cleaning throttle body and even my mas air and my whole cold air intake setup.no change
someone actually told me if i change my alternator it could clear that up for me
but to my knowledge i never heard of an alternator messing up your idle
so i was thinking could it be a possible mis fire or failure in the ignition coil(s)
i tried going to auto zone tonight but they told me its too dark to run my codes
so im going tomorrow
has anyone had any experience with mis fires or bad ignition.
anything i can do to save money would help, if anyone actually got to fix there idle prob

[WarmAndSCSI]

What brand of "universal" O2 sensor? By "near your cat" do you mean before or after it?

Ignition problems rear their heads at high-load and high-RPM, not idle. Same goes for fuel problems. They're always more prevalent when you're flooring it.

The alternator could be the culprit. Bad alternator output can cause the ECU to behave erratically because of bad input signals. Have it tested, it won't cost you a dime.

[Serstylz2]

When my coil pack went bad I had a bad misfire problem, if you notice that when you try to accelerate it "coughs" a few times, or when you're going up hills it struggles and coughs like that it could be a coil pack

[pinoyesv6]

i suggest you just wait and get the code. besides a visual inspection, you're probably just wasting your time trying to guess what it is. it can be a number of things and you can try to fix it, but getting the code scanned will tell you exactly what is wrong.

[bboypowerhouse3k]

the universal o2 sensor i believe is after the cat , basically not the o2 in the exhaust manifold. well i tried to get the codes but i can event get the car out of my drive way with it stalling after 10 minutes of warm or if it its warm it will stall after i start, and i noticed even when its warming up i hear lots of pop sounds, which sounds like a mis fire to me but im no mechanic.
i hope its something simple

[WarmAndSCSI]

I can almost guarantee it is just a P0300 (multiple/random cylinder misfire) code any way. However, there may be another code accompanying it that will help out. Do you know anybody who has an OBD-II scanner you can borrow?

The O2 sensor isn't going to be causing any problems if it's the one after the cat. It's only purpose is to report to the ECU that the cat is working correctly.

You mention coil(s), so I'm assuming you have a 4G64. Is this the case? Because if not, you can inspect the distributor cap and rotor on the 6G72 for excessive wear. If the code turns out to just be a P0300, check the spark plugs, wires, and coils (if you're 4G64).

[bboypowerhouse3k]

well i finally got a move on to autozone and picked up a new battery and drove it down there
and to my surprise the engine is still throwing the same oxygen sensor in bank 1 code and they also tested my alternator and i was told it seems to be fine so now im wondering to myself something gotta be wrong although im not getting much popping mis fire noise as before but its still present and also
when i stop at red lights, although the car doesn't shut off it sure feels like it wants to, almost like its choking to stay on
im wondering if my 4g64 is finished

[WarmAndSCSI]

So is it bank 1 sensor 1 or sensor 2? It's going to bank 1 because your engine is an inline, that's obvious. If it's the primary O2 sensor (sensor 1) that's giving bad readings, then you will probably have fuel trims that are maxed out, usually extremely rich. This will cause a poor running condition.

[bboypowerhouse3k]

that code been poppin up ever since i had the exhuast done,
its sensor 1 in bank 1 so im guessing its the primary o2 sensor
i know about poor sluggish drivin but will that also cause the idle to fail and almost shut the car down .?
although it doesn't seem to be throwing codes for them i think im gonna change them anyway
im referring to the alternator and ignition coils

[WarmAndSCSI]

Yes, that's the primary O2 sensor. Make sure that they didn't somehow didn't swap the upstream and downstream sensors during your exhaust work. The primary (upstream) O2 sensor should have a grey plug and the secondary (downstream) O2 sensor should have a black plug. That only applies if your car is Cali-spec.

Once you've made sure they're in the right order, I'd just replace the primary O2 sensor. It could be maxing out your fuel trims and causing your car to be barely drivable. Horrible gas mileage will be another symptom of running way too rich.

[bboypowerhouse3k]

well from lookin at it nothing looks swapped.
and even though the comp is throwing the o2 sensor code
i drove with the light on for about 2 and half years and it never seemed as though it affected the driving and idle conditions. thats the only reason why i would think it could be something else but hey im in no position to argue it juss time to start checking and and taking things off my list..

[WarmAndSCSI]

That would only make sense if that's the only code the ECU is reporting. That light could have been on from just leaving your gas cap loose or something like that. It will stay like that for 2 years unless you get it cleared or reset the battery.

An O2 sensor could get progressively worse in these situations. The richer the car runs, the more fouled out the sensor becomes, leading to an even worse running condition until the fuel trims are just maxed out. Get your codes read again and see if you're getting a code related to a fuel trim malfunction.