hugie82

I just ordered true dual exhaust for my 82 vette from corvette central. The pipes run side by side following the stock exhaust path. I still have CrossFire injection and I want too know what I can do, to tie in the O2 sensor and the air line that went to the cat? Should I weld a bung and a pipe fitting to tie in?

hugie82

No one has this dual exhaust set-up? I hope I'm not the test dummy

nate99

You can get an O2 sensor bung welded in fairly easily. I don't know anything about the air lines. I'm guessing that you don't have the option to ditch some or all of the complicating equipment.

hugie82

Everything is tied to the ECM, so I'm trying not to upset the check engine light The air line is part of the emission air pump & EGR. The line was tied into the catalitic converter that will now be deleted

MN-Brent

My air line goes to nothing as I have a test pipe. You wont get any check engine light, but you may have issues if the O2 sensor doesn't get hot enough. You might have to consider a 3 wire O2 sensor that self heats to maintain closed loop operation.

For my set-up with test pipe, I get closed loop operation as I can feel the TCC engage in 4th gear, which is a sign that you are in closed loop.

B....

SIXFOOTER

First off, the CCC doesn't even know that the cat is there. The O2 sensor needs to be as close to the drivers side head as you can get, It sounds like you got the conversion that reuses the stock manifolds correct? If so all you need is a bung welded into the new pipe at the top.
If your going to put a CAT back on it will need the air pipe, it pumps fresh air into the cat to keep it hot enough to make it burn off the hydrocarbons. If your not going to use the CAT then you can delete the AIR system completely.

82crossfirevette

I did this to my '82 back in 94/95, dual pipes uninterrupted to a pair of high performance Borla 304's. There was a performance improvement but I couldn't get around the "engine" light coming on. This coupled with the fact that it was a pita getting the car inspected made me reconsider. ... I'd like to go back to dual pipes. Keep up posted on your O2 progress.

a1sensei

hugie82

I'm in N.J. and I just QQed (historic plates) my vette, so no more inspection I was hoping they had a bung welded in but if they don't, I have several welders to choose from. My biggest concern is the engine running smooth and the damn check light. If I disconnect/remove the air pump I think it will trip a code but if I leave it with out plumbing it in, it will be noisy. I can't beleive knowone has used this exhaust from CC Thanks guys for your advise!

terry82

when you make the exhaust system more free flowing [dual pipes,no cat ,free flowing mufflers]the o2 sensor does not get hot enough.check what mn-brent said.

PhyscoVette

I have true duela on my 82, I did this last year and have had no problems I put the O2 sensor it the same place it was on the factory system but in the pass side pipe. I also have hooker block hugers (to get rid of the air pipe crap) I have also done away with the smog pump as well. I have no check engine light that come on because of it and I have taken several long trips in it since then with no problems. But a big difference in power.

later

MN-Brent

I dont want to hijack-got any pics of the hooker block huggers. You can start a new thread.

Brent..

SIXFOOTER

Deleting the AIR pump will not cause any codes if everything else is working, ie: Timing set in the zipcode of 12*, and the carb solenoid adjusted correctly.
If this is an 82 with the crossfire, the portion of the system that deals with the exhaust is the same, it just looks at O2 content and adjusts the mix to get what its looking for. The cat and all of that is Post sensor, the CCC has no way of knowing that there ever was a CAT on the car.
You Might get a code if the O2 sensor doesn't get hot enough, but thats easily fixed with a powered sensor.

hugie82

No problem MN Brent. Brent, did you get any spuddering noise from your air pump line being disconnected? I really don't want to tear into my vette. It is running great except my exhaust is rusted out. I plan to pick up a few horsepower and maybe a few miles per gallon with a basic exhaust swap. I'm going to cross my fingers that the MISSFIRE BUG doesn't get me!

BigEarl

I know a lot of the vendors get them from Allens Exhaust. I was told Ecklers does anyway by a Corvette shop in toen here. My dual exhaust I ordered (from Allens) for my 81 had a bung already in there, but my check engine light would still come on every couple of minutes.

PhyscoVette

Sure ill take some pics this week and post them up

Later

snoopykissedlucy

Here's a spin on the previous question....I am installing a 1981 true dual exhaust with full length headers and dual pipes with a cross-over (not the stock routing but straight back)

The question is, do I need to purchase and place the 70's trans crossmember with the two exhaust holes or will the pipes fit under the 81 trans crossmember?
Header collector is 3 inches and pipes are 2.5 inches with no bungs or O2 requirements.

Thanks everyone!

MN80Vette

I put full length headers and dual pipes running [nearly] straight back on my '80. I just modified the cross member to get some ground clearance.

hugie82

Nice pics MN80vette and Big Earl, have you checked to see what code is being tripped? If its the O2 sensor being to cold I'm going to relocated it closer to the manifold. If worse comes to worse I'll install the heated O2 or spend the money on a nice dual in & dual out converter

JLinCA

I originally went with the dual exhaust from Mid America, and last year switched to the system from Allens. Both systems had the bung for the O2 sensor.
I removed the pipe that runs to the cat, but left the AIR pump on. Never had a problem with the check engine light or anything else.