Filled my Mustang (and my pants) up yesterday.

[Miracle]

After getting gas yesterday, the car sat for a while. After getting in after work and letting it warm up by driving around a bit, I got on it pretty good.

Boost gauge jumped up to its regular 10.5, 11 psi, and about a second or 2 into boost in second gear, I heard a really loud POP. Thinking the worst immediately after, i looked in the rear view, and wouldn't ya know it....


SMOKE. LOTS, and LOTS of SMOKE!!!

But wait... no oil pressure warning light on the gauge... the car still runs smooth, it still revs, and oil pressure hold steady. But the exhaust note has changed. Sounds like I cut all the exhaust tubing after the manifolds off and just left it. It really drones and acts like there no cats/mufflers now.

A few weeks ago I pulled and replaced an oxygen sensor on the drivers side... it looked like this...

It doesn't look like actual PHYSICAL damage does it? It's the sensor that sits inside the cat... so my question...

Isn't this indicative of these cats getting WAY, WAY too hot? And yesterday's POP and smoke was a direct effect of a cat failing or what? I'm kinda guessing here....

 

[DiMora]

After getting gas yesterday, the car sat for a while. After getting in after work and letting it warm up by driving around a bit, I got on it pretty good.

Boost gauge jumped up to its regular 10.5, 11 psi, and about a second or 2 into boost in second gear, I heard a really loud POP. Thinking the worst immediately after, i looked in the rear view, and wouldn't ya know it....


SMOKE. LOTS, and LOTS of SMOKE!!!

But wait... no oil pressure warning light on the gauge... the car still runs smooth, it still revs, and oil pressure hold steady. But the exhaust note has changed. Sounds like I cut all the exhaust tubing after the manifolds off and just left it. It really drones and acts like there no cats/mufflers now.

A few weeks ago I pulled and replaced an oxygen sensor on the drivers side... it looked like this...

It doesn't look like actual PHYSICAL damage does it? It's the sensor that sits inside the cat... so my question...

Isn't this indicative of these cats getting WAY, WAY too hot? And yesterday's POP and smoke was a direct effect of a cat failing or what? I'm kinda guessing here....

Whoa....what cootered that O2 sensor? Is it melted? Is that even possible?

Maybe buy an off-road X or H or Mac prochamber and see what happens?

 

[JEWC_Motorsports]

Search for failed cats and engines. I believe FI and cats dont mix. I want to say somewhere on here there are threads that talk about the cats getting hot and breaking apart and clogging causing the engine to blow.

 

[Miracle]

The car already has a Bassani X with Bassani's high flow cats. I have the test pipes around here somewhere... but I know I'll need a tune.

I seriously don't think it's actually PHYSICAL damage... hence the reason for the photo... maybe someone can look and tell.

 

[JEWC_Motorsports]

http://www.s197forum.com/forum/showthread.php?t=48451&highlight=pulled+muffler

here

 

[Miracle]

I think it may be time to install those Bassani test pipes I've had collecting dust.

 

[JEWC_Motorsports]

Ive read a few threads about cats failing, that looks like the cat failed and the material got blown up against the sensor.

 

[fdjizm]

Holy shit did you melt and o2 sensor? lol had to be something physical.
If not this would be the first time I've ever seen anyone melt an o2 sensor.

 

[Miracle]

I dont think it was blunt force damage though FDJ... definately would have looked different, don't ya think?

What could have hit it HARD enough?

 

[fdjizm]

A very high speed piece of metallic cat substrate? possibly.
the o2 sensor walls are pretty thin, but just a guess.

 

[Miracle]

Would it be a big enough chunk of substrate, when it's only halfway inside the cat? Surely not?

I don't know for sure... won't know until i pull the cats off and look... but wow... exhaust flows that hard and fast, in that short of a space?

 

[psfracer]

Take off your exhaust and inspect the cats---I can almost guarantee they are coming apart. Happened to Don W years ago, it also happened to me. I just hollowed out the cats but reused them--so it looked like I had cats on the outside but they were hollow on the inside.

 

[Miracle]

Right on Paul... I figured you, Don, or Bruce would chime in... I figured that's what it was... but even with whiteish smoke?

Thanks man... I have the test pipes here that came with the Bassani X, but just never put em in... it may be time... that and a tune.

 

[G.T]

i've seen many after market high flow cats get disintegrated clogging up the exhaust and blowing engines.. not many stockers though

which one are you running at the moment?
and what's your AFR like?

 

[loots06]

Well the good news is that you didn't blow your motor. I had a similar experience as the one you described and later found that one of my stock cats failed. I'm glad I caught it before I lost my motor. On start up I noticed the right tail pipe had very little steam compared to the left side. I ended up pulling it off right muffler and found all sorts of debris from the stock cat. That dam thing had nearly clogged my exhaust which could have caused my motor to fail. I'll have pics of all the shit I got out I'll have to post them later.

 

[Miracle]

loots... yeah man post some photos.... I think I'm gonna try to get it out tomorrow. Car sounds like total shit right now.

G.T: At idle the AFR holds steady at a rang of 14.0 on the low side, usually about 14.8-15.0 on the high side.

WOT usually dips down into the 10's. 10.8-10.9... rich as hell.

 

[bigray327]

I've nuked two sets. FI + any cats = doom.

 

[Miracle]

FI + any cats = doom.

I'm starting to hear that more often than not Ray... time for the test pipes I've had sitting around for 3 years.

 

[RedMustang]

o2 sensor

 

[Miracle]

o2 sensor

Nope... already been eliminated from the possibilities. I've burned up 3 of them in a 6 month period, on one bank. It's definately a cat.