Converting to 94-95 headers...

[raroZ28]

I've decided to convert to 94-95 style headers because ground clearance is an issue with me. I was going to go with a Mac header or something with the Y pipe.

What all would I need to make it work? AIR will work fine right? What do I need?

[Injuneer]

The AIR connections on the 94/95 headers are a different diameter than the AIR piping fittings on a 96/97. I believe their are adapters available. As long as you can connect the fittings to the headers, the AIR system will work fine.

The EGR connection is the same on both years.

[raroZ28]

Fred, I hope you see this thread again. Or anyone else that can help.

How many o2 sensors do these cars have? The ORY that came with the headers has a single bung for an o2, but it's welded shut. I'm not really worried about that, I can get it drilled out and retapped, but shouldn't there be more room for o2s?? I haven't looked closely at my stock exhaust, and the car isn't here for me to see, it's in my girlfriends garage across town.

BTW, these macs look awesome. The coating on them is still shiny and pretty flawless. I was going to go over it with a high temp clear coat. Good idea, bad idea?

[94 formula]

The 96-97 models had 4 02sensors. 2 were before the cat and two were after the cat. All the downstream ones do (after the cat) is set a SES light if they read that the cats aren't functioning properly. I see that you have a ORY and it probably has the hole welded shut since it is there for the purpose of getting rid of your cats and you no longer need downstream 02's. You will need to have your two front 02 sensors in they are what tells the computer what the a\f ratio is but it will not effect a thing having the rear ones out other than setting off your light and that can be taken care by having it tuned out.

[raroZ28]

The headers each have a bung. If I have 4 o2 sensors, what do I do about the other 2 that my car has? Each header has one bung, the ory has 1, but it's shut. So I have 4 o2's and only 2 places to put them?

[94 formula]

You put the front 02 sensors in the headers make sure you get them in there and not your downstream 02's. The downstream (02's behind the cat) you just get rid of since you won't have cats. Just unplug them and don't worry about them. You will need to have them tuned out though if you don't want your SES light on all the time. I'd also recommend warming your car up a few times just sitting before you put the 02's in since there have been quite a few people reporting 02's being ruined due to some of the header coating burning off in the first few heat cycles.

[Injuneer]

The quick solution is to replace the after-cat O2 sensors with "simulators" that plug into the vehicle harness, in place of the sensors.

[raroZ28]

Got the car up on stands, it's up enough to get the job done. Fought with the bolts under the car, put some pb on them twice today, went and bought some new tools I'm going to need, and it's all prepped. Those bolts are so tough...

What should I do about the pipe I'm gonna need? My pipe ends a few feet before it meets my catback.

Remember my car is a 97... I'm still unsure on what to do. Anybody else ever done this conversion? I'm sure it's popular with guys who have lowered cars. I just never saw anything on it. Any suggestions? Should I run a 3" pipe from the mac y pipe to my cat-back? I'm not running any cats. No emissions here in MI, and I'm not too concerned about it. If you're going to post here and hate on me for it, just click the back button, I really don't care to hear it Not being a jerk, I just know some people have different views on things and are outspoken, but it won't get us anywhere.

Thanks

[Injuneer]

There's a piece called an "S-pipe" that connects single-cat headers to a dual-cat catback. Check Thunder Racing, T.Byrne, or similar F-Body specialist shops. Or have your local muffler shop make you one.

[raroZ28]

I HAVE THAT! It came with my magnaflow. I hope I'm thinking of the same pipe.


I hope you're talking about that pipe up top right.