Throwing a p0420 with a high flow cat and new sensors months ago now. The headers were put on three months ago so the cat and sensors have been on for.... I can't even remember to be honest. what would cause it to randomly come on?

 

Is it possible your High Flow was poop and it already crapped out?
Or a dead sensor? Only things I can think of.

 

what cat you put on there???

 

If you put a Magnaflow 94xxx series cat on it, there is an internal company "recall" that Magnaflow has on these, they aren't responding well to ethanol. There is a 99xxx series that should be a direct replacement for it and you should be able to pay only the difference for it. The increased caost is due to the larger converter that contains more precious metals than the 94xxx series. Magnaflow's catalog rates the 94xxx at a GVW of 6000lbs and the 99xxx for 7000lbs.

Just had mine replaced 2 weeks ago.

 

Darnit! I honestly forget which cat I ended up getting. I think it was the short case one because I didn't need an o2 extension wire. Time to look up the numbers..... SON OF A B! I have the 94109. When I had the cat installed they guy kept the warrenty paper (I guess so there was no paper trail to him). So even if there is a recall I doubt it would do me any good... I can't seem to find my reciept for the cat either.

I looked up the 99's aim. Looks like I would need the 15.5" cat with no o2's (99409HM)? Its going for 100ish on ebay which isn't as bad as I thought. So this is the cat that magnaflow recommended in lou of the 94's or one that you came up with? Just wanting to cross my t's and dot my i's before I drop some more money. Im just surprsied that I haven't heard much about the failures considering they are recommended so often on here. Also this one doesn't say specifically "high flow" Will it still be highflow or am I better off saving a few $ and pulling my stock cat out of storage and having it put back in?

 

All magnaflow cat's are highflow compared to the stocker.

Check with your exhaust guy about the warranty. Did you buy the cat from him or Ebay? He should have a record of it, if you have a receipt, that should be enough. If he gives you BS, take your business elsewhere and be sure to let him know it.

As far as the numbers, there should be a direct correlation between the 94xxx and the 99xxx, so the 94109 should have a 99109 equivalent. My exhaust guy also told me that if they raise the ethanol standard again, the 99xxx series may not be enough.

I strongly suggest you buy the cat from a reputable shop as then you have a warranty record to go back too. My exhaust guy is really honest and I'll go back to him for anything I need exhaust. Should I need a new setup in the future, I'll be sure to go back to him. Heck, I'll even pay a bit more and order it from him as I know he'll back it up.

 

I have the same prob, and Jeg's confirmed it. I have the whole y-pipe direct replacement setup. Have not had the time to call MF yet. But what I have done in the meantime is the spark plug non fouler trick, no CEL now. So now I'm getting lazy about calling MF.

 

I've gotten one CEL since I had mine installed in like November. I'll have to see if I can find the receipt to see if it's a 94xxx. I'm sure it is. Hell and ****. Thanks for the info Squirrelz.

 

I went to a local store up here at college because they carry them on the shelf and get a 10% discount, then had it installed at a shop at home for $50. I guess I could take a drive up there on monday and see if im at a dead end or not with the store. On second thought the reason I can't find the reciept is because I kept it in the box with the new cat. He threw that box out with the warrenty paper. But I did pay with my debit card so I will see whats up. Aim, thats not exactly what I wanted to hear about the new one may not be enough in the future if they raise to 20% If they did wouldn't that mean we would need new computer flashes, and what would happen to the people with stock catalytic converters (would they fail like these have)?. Well this is rather difficult. I don't know if the non-fouler trick will pass visual inspection and I would rather not chance it. Yeah it will get the cel off, but it doesn't bother me at the moment. An o2 sim would be nice and I could hide it, but... it runs around the same cost as the replacement cat. Also can they tell when they do inspection that there is no variation in the rear sensor? If this cat's efficiency has failed over 6 months, does that mean the ethanol has coated the cat and I should be concerned about it clogging? So many questions... :/ Sorry guys. Just want to make sure I get a grasp on this so I can fix it this time and not be in this position 6 months down the road unexpected again.

 

Also Squirrels, there is no 94109 equivelant (99109). You said the 94109's were 6000lb. The 99409 is the 7000lb in a 3" and guess is the one you had installed. There is a 12" cat 99009, which is 6375lb. I guess if I am going to get one, just get the 7000lb like you did, and another 3" adapter I guess.

http://www.car-sound.com/02product/universal/990.asp