Catless downpipe caused my turbo seal to blow

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Freddy Bader

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Just bought a 2010 lincoln mks eco boost..thought I would get some exhuast work done by a buddy who has been working on cars his whole life.. We decided to do a muffler delete on the 2 rear mufflers and he took the 2 cats closest to the engine off and gutted them. He warned me this would increase the boost psi and in my ignorance I said great! Took it for a test drive and it bogged down. Wouldn't run for more than 5 seconds. We blew the seal on the rear turbo. My question is what do I do now? He said he could take the turbo off rebuild it and put in a new seal but won't this happen again? Do I have to upgrade both turbos now to handle the pressure? Please help!
 

limited02

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im betting no .

I'm betting the same.

OP - Gutting the down pipes could actually decrease PSI because of the improved flow (less back pressure). Your bogging down has more to do with the 02 sensors located after the cats not reading what they expected because you have to compensated for that change (something your buddy should know). Obviously you are going to need a new seal for the turbo, but I would strongly advise you get a tune to correct the issue you made or install new cats. I'm not a whiz at this and I'm sure I'm incorrect about something, but hopefully someone else can chime and and better lay out what I'm trying to say.
 

SilverSH0

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What rebuild kit is he going to use? My rear turbo went out and I wanted to rebuild it but couldn't find a kit to rebuild. I would like to buy one for the front turbo when it eventually goes out.

I'm betting the same.

OP - Gutting the down pipes could actually decrease PSI because of the improved flow (less back pressure). Your bogging down has more to do with the 02 sensors located after the cats not reading what they expected because you have to compensated for that change (something your buddy should know). Obviously you are going to need a new seal for the turbo, but I would strongly advise you get a tune to correct the issue you made or install new cats. I'm not a whiz at this and I'm sure I'm incorrect about something, but hopefully someone else can chime and and better lay out what I'm trying to say.
I'm not sure if it's different on this car. But on normal cars there are O2 sensors before and after the cats. The O2 sensors BEFORE the cat is the one used to adjust A/F ratio and feedback into the system. The O2 sensor AFTER the cats is usually only a sensor to tell if the cat is bad. My Jeep had been running with a straight pipe in place of the cat (cat was stolen at the Indy 500 about 5 years ago). It has a CEL but doesn't effect how it runs.
 

2012korn

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I already told him this on the Facebook page.....Guess he didn't like the answer there. Guessing he won't like it here either.
 

limited02

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What rebuild kit is he going to use? My rear turbo went out and I wanted to rebuild it but couldn't find a kit to rebuild. I would like to buy one for the front turbo when it eventually goes out.


I'm not sure if it's different on this car. But on normal cars there are O2 sensors before and after the cats. The O2 sensors BEFORE the cat is the one used to adjust A/F ratio and feedback into the system. The O2 sensor AFTER the cats is usually only a sensor to tell if the cat is bad. My Jeep had been running with a straight pipe in place of the cat (cat was stolen at the Indy 500 about 5 years ago). It has a CEL but doesn't effect how it runs.

I had an '02 sensor go out on my Ranger and it ran a little rough and got horrible mpg. Swapped it out and all was good in the world. Now I have no idea if the effect is greater on a turbocharged engine vs a N/A one.
 

2012korn

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It is. He isn't tuned for no cats. And most likely his buddy screwed up one or all of the o2 sensors while he gutted them. And now he's blaming the turbo for why it runs like poo.
 

SHOdded

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What rebuild kit is he going to use? My rear turbo went out and I wanted to rebuild it but couldn't find a kit to rebuild. I would like to buy one for the front turbo when it eventually goes out.
Ask Mike at EcoPowerParts.com what he can provide. I believe at one time he had offered a DIY upgrade kit for the OEM turbos.
 

SilverSH0

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I had an '02 sensor go out on my Ranger and it ran a little rough and got horrible mpg. Swapped it out and all was good in the world. Now I have no idea if the effect is greater on a turbocharged engine vs a N/A one.
Not knowing anything I would bet it was a front O2 sensor (pre-cat). When those go out the computer defaults to dumping extra fuel (to avoid running lean and detonation) and it will run rough and get terrible mpg's. Front O2 sensors serve a different purpose than rear O2 sensors.

Assuming this car is the same as most vehicles (which is an assumption because I don't know), a failed rear O2 wouldn't do anything except throw a CEL. I believe it's a good assumption because people are running catless DP's without negative impacts. I'm not a tuner but my guess is they do just like most other vehicles and simply turn the rear O2's off in the tune.
 

2012korn

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Yes catless downpipes with a tune to correct for what the computer is seeing from the 4 o2 sensors......
 

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