Plugged cats?

ummduh · 01-22-2001, 01:00 AM

Ok, well I have an 87 stang, 110,000 miles on the original drive train consisting of the standard 302..

Ok, well I seem to have a performance problem, but the car has been running great untill recently so I haven't really investigated.

The other day, on the freeway on ramp, got on it, and it hesitated for a split second, just enough for the front end to drop back down. Everything was cool after that for about 11 miles.
All of a sudden, the engine just started laboring. Well sounded labored, more than usual. I've got a K&N open air filter, the intake was louder than it ever was.

Well, it bogged and bogged and just kept going slower untill I could get to a place to pull over. Felt like I cooked the trans actually. So I checked, and it only was about a quart low. (getting the trans fluid took about a half hour, so it sat there.) Filled her up and took off, worked great for about a quart mile, then bogged down again. This time I was hearing a hissing from behind the engine everytime you opened the throttle. So I checked to see if I was spitting tranny fluid from a rusted line or something, but nothing. Checked all the visible vacuum lines, all good.

Well, I nursed it untill I got it close to my house, and in a garages parking lot. By now, the engine was running very badly, surging and missing at idle. Wasn't responding very well to WOT-blips either. So I went home and got my code-scanner to see if It had set any codes. I only got thermactor failuer (bank 1 and 2).

Ok, well by the time I got back to it, it was running great. Back to what it was. Drove it home and a couple more miles of around the block driving, seeing if it would do it again. It hasn't. I haven't had the guts to take it back on the freeway, but I've had it at a sustained 55 for a mile or so and it hasn't done it.

The other thing I noticed now is that one of the cats is rattling. So..

Ok, I know this is long, but heres backround on the car.

It sat in a guy's garage for like 6 months as he was trying to get it to pass emissions. He did the exuast (supposedly including a cat, or maybe all of the cats..not sure) before he went on to messing with it.Then the TFI went bad, and would only run at WOT.. while they were messing with it. They weren't computer literate and just replaced stuff as they saw fit. All I had to change to get it to run was the TFI. So I'm thinking that lots and lots of raw gas ended up in the cats also.
The other thing is that this car is a DOG. (before this happened) I'm counting 12-15 second 0-60's. I got my *** whooped by both my 90 G20 conversion van(with a tbi 350), and a freind's 91 automatic escort! I thought these things were a bit better than that.

So, what are your opinoins? Anyone really know how to go about using a vacum gauge to check for exuast restrictions? I think it revolves around that it has to drop to 0psi at WOT, if it doesn't theres a restriction?
Keep in mind it's like 10 degrees out here in WI, and no access to a garage!

Thanks!
Matt

01-22-2001, 08:43 PM

If those cats are plugged they will get real hot, and fast. He replaced the cats? I doubt it, why whould he replace 4 cats@$50 a piece? He could get a performance h-pipe w/cats for not much more, but maybe he did. Has the car had a tune up lately? Is there water in the gas? Hmmm.. Is it getting enough spark? fuel? Have the oxygen sensors been replaced? What makes you think it could be the tranny? Does it do this in any certain gear?

ummduh · 01-22-2001, 11:03 PM

Ok, I thought he said he replaced a cat, but I might be mistaken. I know theres a new midas-style exuast under it. Yea, bad stuffs, but I got the car for $200!

Ok, I changed the TFI (the case was cracked, which is why it didn't run). The TPS, the O2's, and repaired alot of the engine wiring harness. Hmm... the other thing I noticed is a sort of hissing from the gas tank area while it's running, seperate from the fuel pump.

I thought it might be the tranny, cuz I've smoked an AOD before and remembered what it felt like.... But the only time it seemed to do it was at 55 in Drive. (around 2200 rpm). I haven't gotton to do it in the city and haven't had a reason to hit the freeway again.

He did a tune up I guess, but I changed the wires becuase he stuck el-cheapo's on it. Replaced with MSD wires. Haven't looked at the plugs, but he probably has champions in it ..

Umm, i can't think of much else.. I don't think it could be water in the gas, but I stuck a bottle of heet in it anyways. (the red one). Can't really tell if the cats are getting really hot, they don't glow or anything.

Thanks..
Matt

01-22-2001, 01:00 AM	#1
ummduh Registered Member Join Date: Jan 2001 Location: Milwaukee, WI USA Posts: 2	Plugged cats? Ok, well I have an 87 stang, 110,000 miles on the original drive train consisting of the standard 302.. Ok, well I seem to have a performance problem, but the car has been running great untill recently so I haven't really investigated. The other day, on the freeway on ramp, got on it, and it hesitated for a split second, just enough for the front end to drop back down. Everything was cool after that for about 11 miles. All of a sudden, the engine just started laboring. Well sounded labored, more than usual. I've got a K&N open air filter, the intake was louder than it ever was. Well, it bogged and bogged and just kept going slower untill I could get to a place to pull over. Felt like I cooked the trans actually. So I checked, and it only was about a quart low. (getting the trans fluid took about a half hour, so it sat there.) Filled her up and took off, worked great for about a quart mile, then bogged down again. This time I was hearing a hissing from behind the engine everytime you opened the throttle. So I checked to see if I was spitting tranny fluid from a rusted line or something, but nothing. Checked all the visible vacuum lines, all good. Well, I nursed it untill I got it close to my house, and in a garages parking lot. By now, the engine was running very badly, surging and missing at idle. Wasn't responding very well to WOT-blips either. So I went home and got my code-scanner to see if It had set any codes. I only got thermactor failuer (bank 1 and 2). Ok, well by the time I got back to it, it was running great. Back to what it was. Drove it home and a couple more miles of around the block driving, seeing if it would do it again. It hasn't. I haven't had the guts to take it back on the freeway, but I've had it at a sustained 55 for a mile or so and it hasn't done it. The other thing I noticed now is that one of the cats is rattling. So.. Ok, I know this is long, but heres backround on the car. It sat in a guy's garage for like 6 months as he was trying to get it to pass emissions. He did the exuast (supposedly including a cat, or maybe all of the cats..not sure) before he went on to messing with it.Then the TFI went bad, and would only run at WOT.. while they were messing with it. They weren't computer literate and just replaced stuff as they saw fit. All I had to change to get it to run was the TFI. So I'm thinking that lots and lots of raw gas ended up in the cats also. The other thing is that this car is a DOG. (before this happened) I'm counting 12-15 second 0-60's. I got my *** whooped by both my 90 G20 conversion van(with a tbi 350), and a freind's 91 automatic escort! I thought these things were a bit better than that. So, what are your opinoins? Anyone really know how to go about using a vacum gauge to check for exuast restrictions? I think it revolves around that it has to drop to 0psi at WOT, if it doesn't theres a restriction? Keep in mind it's like 10 degrees out here in WI, and no access to a garage! Thanks! Matt

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01-22-2001, 08:43 PM	#2
rbatson Guest Posts: n/a	If those cats are plugged they will get real hot, and fast. He replaced the cats? I doubt it, why whould he replace 4 cats@$50 a piece? He could get a performance h-pipe w/cats for not much more, but maybe he did. Has the car had a tune up lately? Is there water in the gas? Hmmm.. Is it getting enough spark? fuel? Have the oxygen sensors been replaced? What makes you think it could be the tranny? Does it do this in any certain gear?

01-22-2001, 11:03 PM	#3
ummduh Registered Member Join Date: Jan 2001 Location: Milwaukee, WI USA Posts: 2	Ok, I thought he said he replaced a cat, but I might be mistaken. I know theres a new midas-style exuast under it. Yea, bad stuffs, but I got the car for $200! Ok, I changed the TFI (the case was cracked, which is why it didn't run). The TPS, the O2's, and repaired alot of the engine wiring harness. Hmm... the other thing I noticed is a sort of hissing from the gas tank area while it's running, seperate from the fuel pump. I thought it might be the tranny, cuz I've smoked an AOD before and remembered what it felt like.... But the only time it seemed to do it was at 55 in Drive. (around 2200 rpm). I haven't gotton to do it in the city and haven't had a reason to hit the freeway again. He did a tune up I guess, but I changed the wires becuase he stuck el-cheapo's on it. Replaced with MSD wires. Haven't looked at the plugs, but he probably has champions in it .. Umm, i can't think of much else.. I don't think it could be water in the gas, but I stuck a bottle of heet in it anyways. (the red one). Can't really tell if the cats are getting really hot, they don't glow or anything. Thanks.. Matt