Cat removal & the faux firewall...?

[LoloHaole]

I need to do my cats soon and I have read here and there that there is a "faux firewall" in the engine bay that can be removed to allow easier access to the cats and the ability to take them out from the top without as much struggle. But there are no videos on how to do this, and I haven't been able to find any forum posts with description and pics.

Does such a thing exist?

I want to do this so that I can gut the cats, have the flanges reinforced and reinstall them without having to cut anything out.

Thanks,
LH

[soopablogga]

I just did this the other day to borescope my cats via the o2 sensor holes. Somehow mine are fine on e40 stage 2 @ 165k lol.

You won't be able to get them out from the top. I didn't look closely since the cats were fine, but I didn't see any of the bolts to the manifold or DP accessible from there. I'd confirm you actually can do what you're trying to do before disassembling. It's a pain getting it back together. Have a small bucket or towel ready to catch coolant from the heater core hoses.

Here's a guide from ECS. You do not need to disconnect the ECU/battery etc. so just follow the relevant parts. Good luck.

http://bd8ba3c866c8cbc330ab-7b26c6f3...1PPjQSZ-J2MfEQ

[OLDS4]

Following I need to do the same thing.

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[LoloHaole]

Cool, thank you for that guide! It does look like the cowl separation panel is the "faux firewall" I've read about. But yeah...from the pics I can't really tell how much access it gives to the cats. You say you did this to get access to the O2 ports?

Maybe the trick is to loosen it all from the bottom, then pull out the top...? IDK. I'm in the dark with this one, but that link helps, so thank you.

I just did this the other day to borescope my cats via the o2 sensor holes. Somehow mine are fine on e40 stage 2 @ 165k lol.

You won't be able to get them out from the top. I didn't look closely since the cats were fine, but I didn't see any of the bolts to the manifold or DP accessible from there. I'd confirm you actually can do what you're trying to do before disassembling. It's a pain getting it back together. Have a small bucket or towel ready to catch coolant from the heater core hoses.

Here's a guide from ECS. You do not need to disconnect the ECU/battery etc. so just follow the relevant parts. Good luck.

http://bd8ba3c866c8cbc330ab-7b26c6f3...1PPjQSZ-J2MfEQ

[JRYtheS4]

Cool, thank you for that guide! It does look like the cowl separation panel is the "faux firewall" I've read about. But yeah...from the pics I can't really tell how much access it gives to the cats. You say you did this to get access to the O2 ports?

Maybe the trick is to loosen it all from the bottom, then pull out the top...? IDK. I'm in the dark with this one, but that link helps, so thank you.

I just had mine apart. It does allow access to the bolts from the top but I don't believe you could remove them from the top just based on the amount of space.

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[Fresh.S4]

youtube jhm cat removal. thats how you remove them. using this method, my cats came out easily within like 5 hours.

the fake firewall removal im sure helps a lot in accessing that top bolt.

[JRYtheS4]

youtube jhm cat removal. thats how you remove them. using this method, my cats came out easily within like 5 hours.

the fake firewall removal im sure helps a lot in accessing that top bolt.

Yeah I could see the top bolt from the top pretty easily. It's almost a straight shot.

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[LoloHaole]

Thanks Fresh.S4 & JRY, I'll check out that vid today. It sounds like the cowl removal is more about access to the top bolt than it is about navigating the cats out.

[soopablogga]

Cool, thank you for that guide! It does look like the cowl separation panel is the "faux firewall" I've read about. But yeah...from the pics I can't really tell how much access it gives to the cats. You say you did this to get access to the O2 ports?

Maybe the trick is to loosen it all from the bottom, then pull out the top...? IDK. I'm in the dark with this one, but that link helps, so thank you.

Sorry, I didn't get the notification for this. Yeah I was actually planning on pulling/gutting/reinforcing my cats, but got a borescope to check how they're doing before doing so. I don't drive that hard and from my research the cats failing is actually more rare than forums lead people to believe so I decided to leave 'em for now.

I didn't look for the manifold bolts, but recall hearing someone say on FB you can get to them more easily from there. Even with the cowl removed there's not a ton of space to access the cats. There's a couple guides on youtube and they don't pull the firewall. Instead looks like they're able to get to the top bolts through the wheel wells. Then drop the trans and pull it to the side with a ratchet strap. They're using lifts though, might be easier to do the firewall way if you'll be on stands.