Running bad ?

[JDMorrison]

I own a 97 SHO with about 115k and I'm having some problems , about 7 months ago 2 of my cats burned a hole through them and started running kinda rough , so then I emptied the cats out and welded the holes and bolted it back up , so after a month is really started being hesitant with power and running really rough and now it barely wants to start and has no power to even move out of my driveway what could it be ?? Please help I really need my baby back

 

[SHOdded]

Maintenance history? Have plugs every been changed? Problems at the cats will start at plugs/coils or injectors usually.

And, of course, pull codes.

 

[JDMorrison]

Maintenance history? Have plugs every been changed? Problems at the cats will start at plugs/coils or injectors usually.

And, of course, pull codes.

well the only code it throws is a misfire ,but see that's what I was thinking is it might be the injectors but I was really hoping it wasn't that , are they easy to replace ? and how much would I be looking at for them if I need them

 

[98SF19]

Maintenance history?

TPS, IAC, MAF
O2 sensors are probably toast.

They burned holes in themselves? Holy crap. I gotta inquire here since my rear bank cat has been getting very hot recently (which may be a result of bad misses I'm currently having) - Had you noticed it getting hot leading up to the burn-through, like smelling anything when you got out of car or seeing smoke?

I was considering the Magnaflow y-pipe but parts and labor will likely exceed (book) value of car; worth a lot more to me of course. I read recently about fitment issues, but can't remember if it was from a DIYer or feedback from a shop.

 

[stephen newberg]

I used the Magnaflow Y pipe and cats when I redid my exhaust. Well worth it, even if they cost a lot. But they were not even close to the value of the car. I think the last time I checked the car was Black Booked at about $2k or so and the pipe and cats together were only about $350. I had no fit issues when I put them in. This is several years ago now. 4, I think. Maybe 5.

pax, smn

 

[JDMorrison]

TPS, IAC, MAF
O2 sensors are probably toast.

They burned holes in themselves? Holy crap. I gotta inquire here since my rear bank cat has been getting very hot recently (which may be a result of bad misses I'm currently having) - Had you noticed it getting hot leading up to the burn-through, like smelling anything when you got out of car or seeing smoke?

I was considering the Magnaflow y-pipe but parts and labor will likely exceed (book) value of car; worth a lot more to me of course. I read recently about fitment issues, but can't remember if it was from a DIYer or feedback from a shop.

I've noticed it does seem to run hot or atleast smell hot , they day they finally burned a hole through I stopped after I noticed it got louder from the leak and looked and my 3rd cat was glowing red , running hot a typical thing with the SHOs? and I do want to get a new system , looking for a more low throaty tone , any recommendations?

 

[stephen newberg]

Sounds to me like at least the third cat is blocked up due to internal breakdown. I replaced all three cats when I redid mine with Magnaflow and for mufflers used Flowmaster 40s. They are louder and deeper than the stock without being overwhelming.

pax, smn

 

[JDMorrison]

Sounds to me like at least the third cat is blocked up due to internal breakdown. I replaced all three cats when I redid mine with Magnaflow and for mufflers used Flowmaster 40s. They are louder and deeper than the stock without being overwhelming.

pax, smn

well currently all my cats are empty completely but I want to replace the first 2 and possibly delete the last one and just do a 3inch pipe with aftermarket mufflers

 

[stephen newberg]

Then something is very wrong if the third cat is still glowing red. Normally this sort of thing only happens when it is plugged up. Perhaps you need to check it again to see if it is still empty.

pax, smn

PS: I do not know which state you are in, but in some if you delete the 3rd cat you will not be passing inspection and getting a license the next year. Overall, the best thing to do is not to try deleting the exhaust parts designed for pollution control, but rather making sure they are working right, which also, by the way, from most of the dyno research that has been done on these engines over the years, will actually give you the best horsepower and output curve. Those Ford and Yamaha guys apparently knew what they were doing when the designed the engine, including its exhaust system.

 

[JDMorrison]

so I should just replace the whole system including o2 sensors and just get like a catback system for better sound ?

 

[98SF19]

Stephen, I think the red-hot glow was before clearing them out.

Those Ford and Yamaha guys apparently knew what they were doing when the designed the engine

. . . except maybe the cooling system, and the pcv system (along with the plastic gear in the IMRC), and *oh yeah* the super-cool cam sprocket press fit. I still love the car, but there's little doubt in my mind that once the mid-engine idea was scrapped back in the early 90's, the PE's at FMC scrambled for somewhere to put the thousands of 3.4L v8s they'd partnered with Yamaha to build.

 

[JDMorrison]

yes the red hot cat happend before I emptied them , I was just cruising on the highway after work and I noticed my car got louder and and sounded like an exhaust leak(which it was) and when I got home I looked under and it was glowing so I took the cats out and emptied them and put it back on and not to long after doing that is when it really started running bad now now just doesn't want to move

 

[stephen newberg]

OK, in that case you have hopefully cured the red hot cat problem, but yes, in answer to your question, the most straight forward way to go would be replacing everything and for behind the cats picking a muffler you like. However, this is also an expensive way to go.

pax, smn

 

[JDMorrison]

OK, in that case you have hopefully cured the red hot cat problem, but yes, in answer to your question, the most straight forward way to go would be replacing everything and for behind the cats picking a muffler you like. However, this is also an expensive way to go.

pax, smn

yea I probably won't get the muffler right away but after I get it all running good I'll go ahead and get better mufflers , but I just need to figure out exactly what is making the car run so bad , I haven't had it looked at yet by pros which I probably need to before spending all this money on parts

 

[stephen newberg]

[QUOTE
. . . except maybe the cooling system, and the pcv system (along with the plastic gear in the IMRC), and *oh yeah* the super-cool cam sprocket press fit. .[/QUOTE]



I have never had the slightest hiccup from the cooling system or the pvc system (or the AXN4 transmission that seems to give some problems), but yes, the stupid plastic gear in the IMRC is rather nuts and very obviously they screwed up the cam sprocket. However, at the same time, mine has well over 200k on it these days and having wired the IMRC out of the picture and welded the sprockets, it still runs like the proverbial Swiss watch. I had not run it for a couple of months and went out today, attached the battery cable, and it started on just the touch of the ignition. Its a pretty well designed machine.

pax, smn

 

[stephen newberg]

yea I probably won't get the muffler right away but after I get it all running good I'll go ahead and get better mufflers , but I just need to figure out exactly what is making the car run so bad , I haven't had it looked at yet by pros which I probably need to before spending all this money on parts

Are your O2 sensors working?

pax, smn

 

[98SF19]

You said you were getting a misfire code. Sounds like to me it's multiple misfires, which I am dealing with now. I don't think you ever told us the history of plugs and coils as mentioned early on by another user. I had mine swapped out back in like '07, and considering it's a 98, I've gone longer with the ebay versions (search Alanisdeals) currently than I did with the original Motorcrafts (which are apparently the same exact items as what Alanisdeals is selling as "Visteon"). I read somewhere on here that if left alone, misfires will do permanent damage to several systems. I'm a bonehead since I had the whole intake apart and didn't change plugs and coils, EVEN AFTER ANOTHER USER SUGGESTED IT. I can't imagine your sho has gone this long on originals, but considering Stephens account of his good fortune, nothing would surprise me.

There's an exhaust shop just down from where I work, so I may have them do the Magnaflows eventually (no doubt the shosource guys are licking their chops with this thread - maybe they'll give us a discount if we go in together?)

 

[stephen newberg]

I bought my Magniflow down pipe and the cats from one of the discount supply houses. Rock Auto, maybe? I do not remember. It was expensive, but not exorbitant. Maybe $300 for the while thing or so. But, it was a while ago, so things are doubtless higher by now.

pax, smn

 

[98SF19]

Thanks for the info - I'll look around.

FYI to all considering coils and plugs . . . I just got 2 sets of 4 each coils and plugs from Alanisdeals06 shipped for $99. The shipping notification came via e-mail 10 minutes after I put in the order - Wow! Based on my experience, the coils need replacing every 10 years or so. I'm in FL so they might last longer elsewhere.

 

[E1]

I admit I didn't read the whole thread.

Red Hot Cats comes from one thing - excessive fuel. The cats consume the excess fuel to prevent it from going out the tailpipe. That is their purpose. When a lot of extra fuel is introduced into the cats, they get really hot.

Stuck injector/s or poor ignition on one or more cylinders.