UofACATS

With the cats pulled the symptoms remain.




Nice DSM. 95 GSX daily.

UofACATS

I'm going to start looking at distributor cap and rotor, ignition coils, plugs, wires, and grounds.

Any recc's on replacing these items should they require it? Aftermarket OK, or OEM only? I suppose that goes for other items as well, generally should I stay with OEM parts?

Thanks

UofACATS

Also, I plan to re-install the cats and pull each o2 sensor replacing with a wideband to get idle AFR.

Will this automatically result in a CEL?

I expect a nice 14.7 at idle, what should I expect under cruise and WOT?

Thank you

bituerbo

If your cat was blocked it was likely running rich.
I'd say replace your 02 sensors man - see where that gets you.

justfixit

Your problem is one of your ignition coils not firing. Each coil fires 2 cylinders per cylinder head. If one of the coils go bad, you basically have a terrible running 4 cylinder engine. A catalytic converter will only glow red when it is fed with excessive unburned fuel. You have a rich condition. Faulty O2 sensors 99% of the time will go to 0volts which is lean. Your O2 sensors are probably ok. Check ignition coils (probably bank#1 next to a/c compressor) which usually gets hotter due to less air circulation.

UofACATS

From my time spent on iATN, this is also my theory. I have some shop time scheduled, we'll see. I hope (and think) you're right.

Thank you!

GRAND_LS 4

iTrader: (2)

99% its one of your coil packs. Usually the passenger goes out first. Had the same issue on the SC400.

UofACATS

Ordered a coil pack (will test both sides to detemine faulty unit) wire set, and plugs. Try to get to it today.

I looked briefly at the coil. Best way to access it?

UofACATS

Pulled the battery and hold-down hardware. Pulled various covers to access the spark plug wires. Pulled the wire to the coil, it was quite brittle and it snapped right away. Looks like the "extra heat" is real.

GRAND_LS 4

iTrader: (2)

Best way to test out the coil is to unplug it and see if anything is different. It also could be one of the wires.

You are correct though, its somewhat a pain in the rear to access the passenger side coil. I've done this so long ago, i really dotn remember how i did it exactly, sorry.

UofACATS

I should have waited for this response before I started tearing into the car! Really though I realized this halfway through, then one of my friends called and after a minute or two said the same thing. Oh well.

With the battery out, access to the coil is not bad. It's a 14mm on the firewall side and a 10mm on the other. Takes a good 5 minutes of frustration then it's out.

UofACATS

Car runs.

Pulled the plugs. They read as burnt (not firing) and fine. I thought each side had its own coil and I was going to see one side completly fouled with fuel and one side completly burnt.

They came out as follows: Burnt, fine, fine, burnt. Other side: Fine, burnt, burnt, fine. Confusing until you look on AllData and see each coil fires two cylinders on each side. Replaced the plugs, coil, and wire set. Fired right up.

Open manifold V8 sounds good