Bad catalytic converter *it just keeps coming. Try page 3

[1990lumina]

I would stop driving that car now before you ruin the new cat. They don't like raw fuel in them.

[ns87]

I would stop driving that car now before you ruin the new cat. They don't like raw fuel in them.

 

definitely! only drove it the 3 miles home and I was worried about that!

 

#1 My O2 sensor was unplugged I just changed it out a couple months ago, and I guess I didn't plug it in as firmly as I should have :redface:

 

#2 My spark plugs

 

 

Sorry not the best picture. High resolution shows it better. Plug 4 is really black. Plug 1 is a little black. All the others look fine and gap is .045 on all of them

 

Do you think #4 can be put back in?

 

 

[1990lumina]

IMO they are all out, go spend the $12 on new ones to put back in.

[ns87]

Changed the plugs. Plugged O2 sensor back in

 

Ran the car for about a minute. No change. I get a "tick tick tick" sound from the catalytic converter. Car is still running very very rich

 

FSM says to test for a stuck open injector (which is what my mechanic insisted it is the problem)

 

An injector sitcking open can best be determined by checking for a fouled or saturated spark plug(s). If a leaking injector can not be determined by a fouled or saturated spark plug the following procedure should be used.

 

Remove plenum, and remove fuel rail bolts. Follow the procedures in the fuel control section of this manual, but leave fuel lines connected

 

Lift fuel rail out just enough to leave injector nozzles in the ports

 

Pressurize the fuel system and observe for injector(s) leaking

 

That's where I am. No leaking injectors, but I never found a section called "fuel control". I pressurized the system, and none of the injectors leak. No vacuum leaks. No black smoke.

 

Tomorrow I will get a fuel pressure gauge and test the fuel pressure. I have a spare regulator already, so maybe I'll swap that in. I'll also OHM the injectors for shits and giggles. Maybe I'll swap the CTS. I'd really hate to throw another part at the car.

 

Any other ideas for running extremely rich? Bad EGR? And anyone know why my brand new catalytic converter it ticking? Did I kill it already ?

 

Thanks ya'll

 

 

 

[1990lumina]

It's ticking because it's getting extremely hot.

 

 

[ns87]

Fuel pressure 38-40PSI and steady. FPR doesn't leak any fuel out the vacuum line.

 

Injectors each tested between 12.4-12.5 ohms

 

My FSM says coolant temperature sender resistance should be:

 

40 F - 7500ohms

 

70 F - 3500ohms

 

210 F - 185 ohms

It was a little cooler than 70, and I got 2600 ohms.

 

I let it warm in the sun, and I got 1400 ohms. I don't think that is very good, because it didn't even get close to 100 F. Maybe it was 85-90 F. I'm gonna let it cool down and test it again

[ns87]

The sensor is at 70 degrees (roughly) and I'm getting 2555ohms. I guess I'm going to replace it

[ns87]

The car is running extremely rich.

 

FPR is good. Fuel injectors are good. Spark plugs are new. Coolant temperature sensor is good (OHM tested it next to a brand new one). No black smoke. No vacuum leaks. O2 sensor is GM and is about 2 months old.

 

What am I missing? I'm going to get it all back together tomorrow and see if the car is still running rich. The catalytic converter glows red within 3 minutes of running.

 

 

[Brian P]

The fact that plugs 1 and 4 are "black" should be investigated. Those two cylinders are fired on the same ignition coil. It's possible there's an intermittent problem or weak spark as a result of a bad coil or ignition module.

 

EDIT: Reading back, I would also check that this "ticking" that you hear isn't electrical arcing between the coil terminals, or from a cut or other defect in an ignition wire (burn, abrasion, etc) allowing the voltage to arc to the motor. It would be easiest to see any kind of arcing in the dead of night. This is something easy to check and won't cost anything other than a few minutes of your time.

[ns87]

I switched out the 1-4 coilpack with a known working spare. Still the same.

Here's a video

 

 

Now I have this terrible whistling and my car is still misfiring. It's lacking power too.The whistling happened after I took off the Plenum. Maybe its the PCV valve hose? It didn't seem visibly cracked anywhere. I sprayed starter fluid on every vacuum hose and the noise never changed. And bubbles never formed.

 

 

Could this be bad spark plugs wires? I replaced those 20k miles ago. How hard do you push the fuel rail down after taking the injectors out? I put new O rings on them, and the rail bolted down fine. maybe I didn't seat them properly?

 

Just to recap:

 

Plugs - brand new

Wires - 20k miles ago

CTS - Hooked it up to a multimeter. It has the same resistance at the same temperature as a BRAND NEW one (tested side by side)

Injectors - all between 12 - 12.5 ohms

Fuel pressure 36 - 40 and steady. Never drops, so I know an injector isn't stuck open or FPR isn't working

O2 sensor - new two months ago. GM

Catalytic Converter - brand new

Exhaust system - 2 years old

Coil packs -  1,2 years old

ICM - 2 years old

PCV valve - brand new

 

I guess I'm gonna change spark plugs wires? maybe go get a junkyard computer?

 

I know this is a lot of information guys, but I'm stuck at my parents house until I fix my car. I was supposed to be back at my apartment a week ago.

[Brian P]

Yeah, that could be the PCV line or some other vacuum line that came out or cracked. Maybe it's cracked at the bend just under the intake manifold? Maybe even a manifold gasket didn't line up perfectly, or something foreign is on the mating surface, or the TB gasket isn't sealing right, etc.

 

You changed the coil and no difference (assuming you ran it with the replacement coil AND this is before the vacuum leak occured) The next thing to look at is the ignition module.

 

Wires could be bad, I've had wires fall apart after one tuneup (the cheapy autozone ones). The fuel rail needs to sit down low enough that the 2 bolts just keep it in place. Lots of people will lather the o-rings with motor oil to ease installation and sealing.

 

The computer is a possible culprit, but I can't say for sure if that's it. I'm leaning towards ignition related failure before the ECM.

[spiderw31]

Well that whistling is definitely a vacuum leak. I'd guess that either a vacuum line is cracked, or a gasket isn't in properly. As for the misfire, get your hands on a timing light, and check to see if any plugs simply aren't firing. Since you've noted the buildup on plugs 1 and 4, I suspect you'll find they are not firing. Also, since you've installed a known good coil, I'd agree with Brian P... get the ICM checked.

 

Good luck man!

[ns87]

Gasket wouldn't surprise me. This is the first time I've ever torn into an engine.

 

I removed the ICM and I'm going to go get it tested. I have a spare ICM which I am also taking to get tested.

 

I guess I've done this enough, got all 3 coil packs out in 20 minutes. Last time I did this, I gave up and left the middle coil pack lower screw out. This time, I think all the lower ones are staying off, what a pain!

 

I'll be back. thanks guys

[ns87]

Three cheers for Brian P. And everyone else who helped, thank you. The ICM failed advance auto's tester. Sure enough, my spare passed and my car runs fine. The old one only lasted 2 years. I looked on the back and sure enough, "Made in China"

 

I guess the ICM failed first, ran rich, killed the catalytic converter.

 

The squeal is there, but that is for another day. Its not as noticeable with the stereo up

 

Again, thanks everyone

[Brian P]

sweet, glad it's done! I'd fix that whistle soon though, being that the fuel delivery system is MAP based, the manifold vacuum reading must be accurate. Having a large leak may screw around with that, and the car might start fighting to keep idle within range.

[spiderw31]

^ What he said.

 

Glad to hear you got it running. Out of curiosity, what brand was the module that failed? Oh, and if you feel inclined to get all the bolts back into all the coil packs, its not to hard if you use a a 1.5" or 3" extension on a 1/4" drive socket. I've had mine on and off nearly half a dozen times now, and I can do it in about 15 minutes now

[Night Fury]

^ What he said.

 

Glad to hear you got it running. Out of curiosity, what brand was the module that failed? Oh, and if you feel inclined to get all the bolts back into all the coil packs, its not to hard if you use a a 1.5" or 3" extension on a 1/4" drive socket. I've had mine on and off nearly half a dozen times now, and I can do it in about 15 minutes now

 

Yep, I'm also getting damn quick at it. Fuckers.

[ns87]

Not sure of the brand. It was the only one advance auto parts carried two years ago. I will take care of that leak sooner or later. the car made it back to my apartment with no problems (100 miles), so I'm happy. Thanks again everyone

[spiderw31]

No name brand FTL . Thats why I forked over the extra for the delco ICM. I may be getting quick about changing it out, but I don't like doing a job multiple times, nor to I like the inevitable skinned knuckles I get when changing the ICM. Not to mention getting stranded on the side of the road .

[ns87]

I'm bumping b/c I went to tackle the vacuum leak. PCV valve line wasn't cracked. None of the other vacuum lines were cracked.

 

Replaced my Plenum gaskets and I have a new problem, but the whistling went away .

 

The car sounded fine when I first started it, then started "chug chug chug chuging". Something isn't right.

 

I had trouble keeping one of the plastic tabs on the plenum gaskets on. I'm afraid it might have fallen off into the intake. I'm 90% sure this didn't happen, but if it did, would my car sound like that?

 

I'm also thinking the stupid PCV vacuum line slipped off the metal nipple. I looked at it (after it was all back together), and from what little I could see it was still on there. There was about 1/2inch of the metal nip still showing (haha)

 

Any ideas? The car seems to have full power, but something sounds very amiss. It's not quite a misfire, and there's no raw exhaust smell.

[Captain Ficho]

Everything you describe sounds like an EGR valve on the fritz, my LQ1 is doing all that stuff and throws Code 32 for EGR valve failure a lot. I tried cleaning it, changing the gaskets, cleaning the port to the intake, everything, but it just keeps doing it. That would be my uneducated guess.

[Brian P]

will it rev freely now? Is the vacuum line to the MAP sensor okay?

[ns87]

I went out and checked it. Once I took it for a drive, that odd chugging went away and all was well. The whistling came back slightly, so I guess the plenum wasn't at fault. I'll check the EGR and throttle body bolts next. But the car drives fine now.