O2 light on, new sensor, light still on and missing bad!!!!

[dubchickshubby]

So The O2 light comes on. I find a plugged cat is the culprit (I really need to drive her car more often) and it fried the sensor. I knockedd the guts out of the cat as a temporary fix and I put in a new O2 sensor on the missus' cabby (just before leaving to go to the ME Dub meet, sorry Sixs). All's fine for about 1/2 hour and then it starts missing. Got so bad that I had to limp it back home with the pedal to the floor and maxxing 60 mph.
So now I'm going crazy trying to figure out just what the hell it is. The light is STILL on by the way...
Weird how it will idle fine and then suddenly lurch into a stumbling fit and then level out again only to restart the cycle all over. If the A/C is run or it's put into gear it stumbles so bad it acts as if it wants to stall.
Does something need to be reset somewhere, or did more demage occur from the plugged cat?
It's amazing how if the a/c drops 10 degrees I hear about it instantly, but something like a major drop in acceration and high running temperature isn;t mentioned at all until the O2 light winks...

[Briano1234]

Try knocking the muffler off or the resonator. If they have collasped internally then that could cause the condition that you are having, had that happen to a toyota that my wife owned drove me crazy trying to figure that out. (rebuilt the carb 2 times).

She complained about only able to get up to 40 mph. I would drive it and get up to 100, but she would drive it and only get to 40....

Also I wouldn't think that a plugged cat would cause the o2 to go bad, it is usually the other way around (least in my case).

I would start at the basics, clean all grounds, check the timing to see if it is dead on. Then drop the muffler and take it for a spin.

My wifes fooled me because from the underneath the muffler looked brand new. Only after I dropped it did I see all the rust on the top.

I took a sawsall and opened it up, and there was a diffuser that was plugging it, the damn car started fine and idled great....but under load it choked and puked.

The kicker was that under load, the gas and air would shoot straight up outta the carb.....

[dubchickshubby]

Thanks Briano. (Love the new avatar!)

I went through that last week. The sensor fried from the excessive heat and backpressure. It was cooked white and plugged solid.
I'm targeting the sensor because after unplugging the cat and running it for a week (much improved performance) the light hadn't gone out, so I changed it (stupidly) just before a trip and it's the only change that I've done to the system before this problem.
I've got an intermediate pipe and muffler from my scirocco that I will swap out since they're new, but the muffler hangers are slightly different and mods will be necessary. The muffler in her is slightly rusted, but breathing pretty freely. You should see all the damn blue smoke coming out now that the cat is unplugged. Rings anyone?
Who offers a good rebuild kit for the SOHV 1.8? The rocco's mill is the designated donor for her car, but since the backup block will be out and accesible, the "might as wells" kicks into gear...

Another thing that comes to mind. She was pressure washing the car a hour or so before we left. Wet fuse block perhaps?

[Briano1234]

now comes the truth....

I pressure washed my rabbits engine 3 times (totally greasy mess).

It would idle fine

pulling it out of the bay was fine.

Trying to get it in to highway it sputtered and puked and generally was crap.

the first time I washed it I left the engine running.

the second time I washed it engine off nothing happened ran great.

the third time I washed it it idles fine but then choked puked and sputtered itself to death.


I don't know if you have digi or not, I do. But I took the connectors off and sprayed wd40 on all the connectors inside and out, I also took off the connectors for the injectors, and the o2 idle position, and everyone I could see......

Presto ran just great.

Also if you can get it in a dark room (garage with all the lights off, and windows covered, have some one start the car, then step on it.

Look to see if you have carbon tracking on the Dist wires or else where. you will see them. Be sure to vent the exhaust.

I had that happed on a 67 midget I had, left me stranded. Later on a friend of my fathers happened by, and in 2 minutes he fixed it by removing the carbon traks with a pen knife.

I have since then sprayed every connector with krylon clear, and it never happened to me again.

I don't have a water leak over my fuse panel yet. (But I need to kill the rust on the windshield or i will).

I have heard of that same indication happening with a soggy fuse panel, It may have dried and the carbon tracks are killing you.

Almost sounds as if you have a bad spark wire....

[dubchickshubby]

Almost sounds as if you have a bad spark wire....
_________________
Briano


BINGO!!!!!! Give that man a ceegar!

I can't believe I missed it! I'm out there tearing my hair out (not that I got much to begin with) because I changed the damn sensor. I tried swapping out the spark unit from the donor, no fix. I tried all connectors, vacuum lines yadda yadda.
Whever it missed I could hear a snap, but with all of the other noises that come out of the 1.8 sewing machine engine in these things, I couldn't pinpoint it.

The timing light was firing intermittently. Hmmm. OK back to basics and forget all of these electronic doodads. I made a light shroud (blanket over the hood) and there it was. #1 wire was arcing to the cap! EASY fix.
The donor's wires and cap are now on it and it runs fine. Too bad it's too late to run up to Maine rally 4.5 hours away to hook up with Sixs.

Thanks for the help Briano! If I hadn't found it by now, it's good to have guys to point out the obvious.

At least I stuck to ol' Butch Bohunk's advice: "Don't go f***ing with the carburation 'till ya get get yer sparks straight!!!!!" (The Last Open Road, BS Levy)

[Briano1234]

awe looking down at the dust scraping the dirt with my feet, shucks tweren't nothing....glad to be of help.

At the same time I was assisting you I was setting the Camber on my van. Seems the IDIOTS at the alignment place wouldn't do it unless I paid 69 additional per tire. My question is how can you set the toe if the wheels aren't flat to the ground....

Got my cheap alignment gauge from harbor frieght.. and the som bitching alignment isn't right on the van....flipping IDIOTS, I am going to take it back and Bitch some more...


Checked the bunny, and it is dead on, so it can't be the way that I am using it.....

Maybe later in the week I will just set it my self..

[dubchickshubby]

Alignment is something I never got into. I understand the concept, but it's like rebound dampling. Too many variables to play with.

69 bucks a wheel is indeed a ripoff! I got my tires at Town Fair. They include an alignment with the install, and give you nice printout afterward.

Years back I tried tying a carpenter's level to the tire vertically and adjusted that way. Wound up taking it to the local garage afterwards anyway.

[kamzcab86]

Didn't read that the OXS light had been turned off.... if it hasn't, white (or red) button on the counter box (speedo cable goes through it and is attached to the fire wall) -- press the button in with a pen/pencil.

[dubchickshubby]

The light IS still on. Thanks Kammy you da best!

Now that I know the secret do I have to be shot?

[sixsracing]

So that's where you were. Scanned the parking lot a few times for a CT plate with a red cabby attached and came up empty. Now I know why. Missed a good show, got lots of pics to post up though.

[dubchickshubby]

Sorry I missed it. The family was pretty disapointed as well. I had PM'd you my cell # in case you had trouble finding me. Obviously you did!
It kills me that it was so stinking easy to fix and I missed it. It was the first thing I looked for when we pulled over on the highway, but it was too light out to see the problem.

[sixsracing]

Never got your PM. Doesn't sound like it would have mattered.

[kamzcab86]

The light IS still on. Thanks Kammy you da best!

Now that I know the secret do I have to be shot?

Nope, no need to be shot; it's not much of a secret these days

[dubchickshubby]

It didn't work! Tried it both running and shut down.
What am I missing?

[kamzcab86]

Keep the engine/battery off. Slowly push the button in using a thin pen/pencil until it stops. Make sure the electrical connection is plugged in (heck, try unplugging it after pushing in the button then plug it back in).