Clogged cat, or fuel problem?

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warrioralumni08

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So, after fixing my "gear display data error" issue, I would like to discuss my next problem with the car. When going WOT, after 5k, the car has a hard time accelerating, it's trying, but it seems like it cant, and you can hear the exhaust popping, and cutting in and out. Still have the factory 3 cats, but no mufflers at all. Sometimes I can smell the "rotten eggs" smell, but that's when I go WOT, but sometimes it wraps to 6k with no problems. It seems like it only accelerates fine, when the car really gets warmed up. If it were a clogged cat though, when the car got hot, I am sure it would cut off, no? I believe I wouldn't be able to go that fast either. On the fuel side, I do have a Walbro fuel pump, and a brand new fuel filter, and also sea foamed the engine twice. Could it possibly be a bad/trashy fuel pressure regulator? Oh, 97 Gen 2.
 
Get rid of that 3rd cat and get an H- or X-pipe (unless you have a base model with single exhaust, then get a Y-pipe) fast!!! Same thing happened to my '97. Rotten egg smell at WOT every time I goosed it. Cut off the 3rd cat and put in an H-Pipe and no more problems. That's what it sounds like to me. I could be wrong but that's my first guess. Those big 3rd cats have a tendency to clog.
 
Don't clogged cats usually cause acceleration problems far earlier than WOT?

I don't know, that's why I'm asking.
 
sprocket said:
Don't clogged cats usually cause acceleration problems far earlier than WOT?

I don't know, that's why I'm asking.
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Its generally not noticed until you ask the car for power and it doesnt aqueous your request

If its a base model... get duals :) Y pipes are for Slowmobiles
 
I'm probably the only one here who doesn't know how my Mark VIII reacts at WOT.:rolleyes:
 
sprocket said:
I'm probably the only one here who doesn't know how my Mark VIII reacts at WOT.:rolleyes:
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Well there is the source of most of your problems. They need to see WOT regularly.

Cleans em' out and keeps em' regular. My third cat smelled a bit when I first got it but it sure does not now.

If you can start your pass at under about 30 mph she will grab first and if you do it just right you can do the 1-2 shift at, well 6000 RPM in my car, right beside your victim's door.
 
Its not misfiring at all, as the engine runs really smooth. The only code I have is p1414 and that comes back to secondary air injection, which I dont think would cause such problem. Before I got home, the car did 0-80 Just fine at WOT, with no rotten egg smell. By then the car was driven at least 30 miles or more and the fan was running. Like I said, when it gets really warmed up, it has no problem whatsoever acclerating. Really only seems to do it when the car is cold and still getting up to temp. Also, my car quickly screeches when shifting gears at WOT? No idea what it could be. Kind hard to describe but its quick, and does it as soon as it shifts into the next gear and that's it.
 
Ill try and do the exhaust soon maybe, if somebody can quit telling me, 'no 2.5 true duals wont fit under there'. Well, apparently your in the wrong profession. I could do the Y pipe myself but I would rather have the true duals! Would MIL eliminators be required, after removing the third cat btw?
 
warrioralumni08 said:
Ill try and do the exhaust soon maybe, if somebody can quit telling me, 'no 2.5 true duals wont fit under there'. Well, apparently your in the wrong profession. I could do the Y pipe myself but I would rather have the true duals! Would MIL eliminators be required, after removing the third cat btw?
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Nope, no O2 sensors back there.
 
warrioralumni08 said:
Ill try and do the exhaust soon maybe, if somebody can quit telling me, 'no 2.5 true duals wont fit under there'. Well, apparently your in the wrong profession. I could do the Y pipe myself but I would rather have the true duals! Would MIL eliminators be required, after removing the third cat btw?
Click to expand...

93-95 only have pre-cat O2 sensors.
 
warrioralumni08 said:
Ill try and do the exhaust soon maybe, if somebody can quit telling me, 'no 2.5 true duals wont fit under there'. Well, apparently your in the wrong profession. I could do the Y pipe myself but I would rather have the true duals! Would MIL eliminators be required, after removing the third cat btw?
Click to expand...

You can fit 3.0" duals under there.. its been done on several Marks
 
You should probably get rid of that Walbro fuel pump. They're not made for the variable signal that the Gen 2's send to them. You need an SVT focus pump...

Not saying that's 100% your problem, but it's probably not helping. It'll die quite prematurely.
 
97MarkJA said:
Nope, no O2 sensors back there.
Click to expand...

Yea, I should have known. Was thinking differently. Doh!

Sapperfire said:
You can fit 3.0" duals under there.. its been done on several Marks
Click to expand...

I try to tell guys 2.5, but their expertise denies such thing. One more shop I can try though.

98lincmk7lsc said:
You should probably get rid of that Walbro fuel pump. They're not made for the variable signal that the Gen 2's send to them. You need an SVT focus pump...

Not saying that's 100% your problem, but it's probably not helping. It'll die quite prematurely.
Click to expand...

Ill take it into consideration, as I have another walbro laying around. Thanks for the tip, but the walbro is kinda loud though. :/


Well, It wasn't the third cat...sigh. So, that leaves the two primaries. Any product I can use to break up the soot in them? Or am I going to have to take a punch or something similiar, and hollow them out? Really don't want to drop the engine just to cut the cats off, would rather hollow them out over that anyday.
 
I've had to hollow out a few cats for people in the past. I always used a old 1/2 drive extension.. Long one or a piece of old black pipe. Make sure you wear a mask when you do it, you don't want to breath that stuff in.
 
Problem still persists, seems like it may be getting worse. Car wont even wrap around all the way, as it used to when it really got warmed up, now it just has trouble pulling past 5k at wot all the time, so I do want to assume it is the cat, but if it starts at 5k all the time, it would seem to be, in my opinion, a fuel or ignition problem. I do have some new cops coming in the mail, and if that doesn't address the issue, then I am sure it will most likely be the cat. Also, driving down the road, when put in neutral, the car would on rev to 5200 it seems and bounce off like it was redlining? That's not normal is it?

On hollowing the cats, I talked to the guy, and he said he could cut the bottom pinch weld, open it up and start removing material, does this sound right?
 
warrioralumni08 said:
Yea, I should have known. Was thinking differently. Doh!



I try to tell guys 2.5, but their expertise denies such thing. One more shop I can try though.

This tells us one thing.. they're not "experts"


Ill take it into consideration, as I have another walbro laying around. Thanks for the tip, but the walbro is kinda loud though. :/


Well, It wasn't the third cat...sigh. So, that leaves the two primaries. Any product I can use to break up the soot in them? Or am I going to have to take a punch or something similiar, and hollow them out? Really don't want to drop the engine just to cut the cats off, would rather hollow them out over that anyday.
Click to expand...

I'd hope you have a pneumatic punch
 
pneumatic punch works wonders. 2lb sledge and a old piece of black pipe works too.
Make sure you wear a mask and glasses. It makes a mess.
 
sounds like a weak torque converter? as they get old and weak when cold it will fall on its face at higher rpm's say 5000 rpm's it will act like a rpm limiter but run more normal 6000 redline when warmed up still weak but not as noticeable as it is was when cold.
 
doubt its torque converter.

remove the O2 sensors and drive it around. it'll be fine, it will just stay in open loop. WOT is easy enough for the computer even without O2s.

if it runs better, its cuz the gas can escape through the O2 sensor holes and you need cats.
 
Or use a temp gun and see where the entering and leaving temperature is.

Mine was a dog when the MAF was dirty would not even think about WOT with the skinny pedal on the floor.
 
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