Quick AIV Question

[IonZ32]

I am looking at getting a set of test pipes for my N/A in hopes that I can prolong my catalytic converters' lives for the next emissions check in a few years. (a set of cheap test pipes is a lot better than buying new cats!) I have read the AIV delete guide ad such, but would prefer to keep that equipment on the car.

From what I read it looks like I can plug the rubber lines that are in front of the cats and keep them on the car without any problems, however I wanted to check with the you guys before doing so. Would you see any problems with keeping everything intact but just blocking off the rubber lines that lead into the test pipes?

[t.mcginley.jr]

While Nissan did get rid of the AIV system after 1992, and probably 99% of Z owners delete them, I think it's actually a pretty cool system since it helps the cats work more efficiently. I actually left my AIV's intact and managed to find someone who had a pair of midpipes made by a muffler shop with magnaflow cats and AIV ports.

As far as I know, none of the aftermarket NA pipes come with AIV ports, you would have to get someone to weld some in (shouldn't be hard for a good welder or exhaust shop). As for temporarily blocking them off, I think it would be better for you to may screen them off instead of actually blocking them. I'm just thinking logically here, but since the AIV tubes are actually pumping out fresh air, it might damage the system if you block them off. If you screen them off (literally with some kind of screen material), it would keep out most debris and still let the AIV system pump air. It would just pump air into the atmosphere instead of your exhaust pipes.

Now that I just wrote all that, I don't feel like deleting it. But I just realized you could probably just put some rubber caps on the AIV tubes and then disconnect the AIV solenoid. That should stop it from trying to pump air. Then just reconnect it when you wanna use it again.

Btw, Magnaflow sells universal high-flow cats on ebay for ~$67 each, in 2" and 2.25" (I think)

[IonZ32]

Those magnaflow universal cats wont clear emissions in CA. Despite what they may claim, the smog shops always run the number on the cat, and it has to be the stock ones.

I've welded up a lot of exhaust systems so maybe I'll just weld some AIV ports on there. I am cutting up a set of cheap TT test pipes and welding in a bend to make them work with my, n/a, so nothing too bad I guess

[t.mcginley.jr]

Oh yeah I was assuming you were in one of the other 49 states haha my bad. Even with my cats and AIV system intact I still failed emissions inspection twice in NJ. I finally passed when I did the vacuum line trick

[IonZ32]

I'll need to look that up then, a buddy of mine has a 93 Z32 with 122k and he keeps failing Hydrocarbons by like 1. We've changed the plugs and the car runs solid. It does have the old style PTU which could be a contributor, but not quite sure.

[Ace2cool]

Despite what they may claim, the smog shops always run the number on the cat, and it has to be the stock ones.

Never had that happen to me. Good thing about CA is you can find a place that's a little shady and get it done from someone who doesn't really care. AZ is the one you have to watch out for, cause those smog offices are government run.

[IonZ32]

Hahaha, yeah I would love to find a shady one! Most of the ones in my area are pretty legit, maybe I should be headed out towards Ione in the backcountry!

[t.mcginley.jr]

I'm starting to think NJ isn't that bad anymore haha we have to get ours inspected (just emissions) every 2 years, but you can either take it to a state inspection station (free) or a certified private one (not free). When my Z failed twice at the state one I was getting ready to pay $75 to just get a sticker at a private one, but I figured I would try the vacuum trick just for the hell of it.