California Smog Conversion

acorad wrote:Here's mine:

(PS: And I'm glad you had me take these pics. I just looked at them an realized my O2's are after the collector/cat flange. I can hear leaks from the flanges and that would explain why I'm getting P0171 and P0174 codes for Lean Banks, as air's getting in at the flanges and telling the O2's that there's a lean condition. And why my LTFT's are 20%+!)

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Very helpful!!

Wow, it looks like the cats have been rotated and new pipes welded to put them in that position. So the BAR Referee had no issues with that configuration?

I didn't do the swap, so I can't speak for sure about what was done with the cats, but the swap did get a BAR sticker. All I do know is that I had a shop replace the driver's side cat, and they did it by cutting out the old cat and welding in the new one.

acorad wrote:I didn't do the swap, so I can't speak for sure about what was done with the cats, but the swap did get a BAR sticker. All I do know is that I had a shop replace the driver's side cat, and they did it by cutting out the old cat and welding in the new one.

Well, you setup is much easier than what I had in mind, I will give this configuration a try and see what happens.

Thanks!!

I hope it works for you. As a reminder, the car no longer has the OEM exhaust manifolds. I don't know if the PO modded the cat's pipes when he installed the headers.

acorad wrote:I hope it works for you. As a reminder, the car no longer has the OEM exhaust manifolds. I don't know if the PO modded the cat's pipes when he installed the headers.

Good point, I can't imagine some one modding the whole setup just to add new headers, I can see someone modifying the collector pipe.

Do you know what aftermarket headers were used? based on the length of the collector pipe, they could be RH headers.

I believe they are RH.

What happened to your oil pan!

87-944S wrote:What happened to your oil pan!

Note to self: Don't leave your sledgehammer standing handle-up under your oil pan when you lower your lift. Doh!

[quote="acorad"]Here's mine:

(PS: And I'm glad you had me take these pics. I just looked at them an realized my O2's are after the collector/cat flange. I can hear leaks from the flanges and that would explain why I'm getting P0171 and P0174 codes for Lean Banks, as air's getting in at the flanges and telling the O2's that there's a lean condition. And why my LTFT's are 20%+!)

Yes, that is a bad thing when you have a pre cat O2 sensor behind a leaky flange, I had that configuration with a leaky flange and had to go open loop to get the car to run properly. The best place for pre cat O2 sensors is behind the flange like the stock LH Camaro exhaust manifold, its funny how the RH O2 is on the Cat pipe after the flange.

I don't see any rear O2s, have they been deleted?

pormgb wrote: The best place for pre cat O2 sensors is behind the flange like the stock LH Camaro exhaust manifold, its funny how the RH O2 is on the Cat pipe after the flange.

I don't see any rear O2s, have they been deleted?

I agree, my gas mileage has been getting worse and worse, I assume due to fuel trims being 20%+.

I've carefully tightened the nuts/bolts on both flanges, especially the DS flange, 2 or 3 times now, but they continues to come loose. I need to find a better way to secure them, I think I'll try nylon-insert lock nuts.

I'm pretty sure the rear O2's are still there. It's been so long since I was underneath it I don't remember for sure.

you might want to rethink the nylon insert (nylock) idea... it gets a bit too hot down there for the poor plastic. ahem, guess how i know, ahem. however- after the burning smell wears off, the glob left might be enough hold the nut on.

try a pinched head locknut.(thread killers though).

Ha! I was wondering about that. I've been googling with no luck, do you have a link to a pinched head locknut?

really? mcmaster.com -- the evil yellow book! somewhere about page 3184-3186... i got distracted.

My "evil yellow book" has welding supplies on those pages. :-)

I did look at all the MMCarr lock nuts, and then found copper-clad lock nuts made for exhaust applications here:

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And here:

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Anyone have any experience with these types of lock nuts?

And then there's this kind too, which seems to have a different method of locking: [You must be registered and logged in to see this link.]

Have you looked at Stage 8? [You must be registered and logged in to see this link.]

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Locking collector nut assembly.

a couple thoughts @ locknuts- the pinched head (3 punches on top) dig into the threads and are wider than most "normal sized" nuts of the same flavor. good for spreading the load over a slotted exh. flange for example. the "multi slotted head" is much smaller so you gain socket room.
i have used stage 8 stuff- great product.
that said, i watched many an exh system installed using the 3 punched nuts with zero failures- simple, install and forget, no concern about if the retainer clip is there after the fact...

plus the fact that mother nature will add her locktite (rust) to the exposed threads may also help...

suboptimalfit wrote:a couple thoughts @ locknuts- the pinched head (3 punches on top) dig into the threads and are wider than most "normal sized" nuts of the same flavor.

I still can't find any lock nuts with the name "pinched head", is one of these what you are talking about?: [You must be registered and logged in to see this link.]

Distorted thread looks like a winner

my favs are the "oval lock with conical top"...what a mouthful- no wonder you couldn't find 'em.

Making good progress, I have got all the electrical work done related to new solenoids and air pump, I now reed to reprogram my PCM. I found a set of Camaro cast intake manifolds, they look pretty stock.

I still have two major tasks, I need to install the steering joints, I decided to go with Borgeson joints and D rod $$$$. The final task will be fabrication the cat's and pipes, that's going to be an interesting job.

I also decided to install some parts I had laying around, I installed tubular control arms with late offset spindles, hubs and 996 TT Big Reds. I also installed a Griffin Radiator with three relay fan setup, and hooked up the heater.

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Nice strut brace, who makes it?

87-944S wrote:Nice strut brace, who makes it?

I am really not sure, I bought it of Ebay a while back.

I almost lost it due to the Hydroboost but was able to fabricate some remote reservoirs.

Got the drivers side exhaust manifold back from a local machine shop, they milled it at 10 degrees to clear the steering shaft, I also had to trim the heat shield.

Drivers side stock Camaro cat with custom down pipe, I used the stock Camaro manifold flange and later added O2 bungs.

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