bgchrs2001

well im planning on building a 306 for my dd andi need everything to be emissions legal. i have everything worked out on the build but my question is on tuning. if tuning involves changing the a/f mix in the pcm then wouldnt that make me fail emissions? im sure i would get a lot more power from a tune but i still need to pass.

my plans are a summit 306 rotating assembly, e303 cam, afr 165 heads(61cc emissions legal), 1.6rrs, explorer u+l intake, still debating 65 or 70mm tb. and maybe further down the road, vortec v-2 sq

and should i also move up to 24 injectors?

mjr46

a tune done right could actually help emissions.....by dialing in the fuel and spark tables to where the a/f is at an optimal range.....but it all depends on how much you spend with a tuner..most may only focus on the wot side of tuning....cause this is where most are concerned with optimizing power..however alot of tuner will often spend time on the drivability side of tuning like idle quality and normal driving to clear up any issues there

Rajun_Cajun

I have AFR 165's, E-303, Performer 5.0 manifold, BBK 70mm TB, Hedman shorties, and a BBK catted H-pipe and i still cant pass emissions. All of those parts are supposed to smog legal. The question isnt, should it pass smog, but will it? It could also be my tune. The previous owner had the stock computer re-mapped. Take that into consideration.

TwoToned306

+1, your odds of passing an emissions test are greater after the tune. The dyno I went to was able to delete any obd code all together, so that nothing would show up. And im not just talking about reseting the computer, I mean actually delete it from the system.

302army187

see this is what im wondering about too, id love to do all these crazy radical things to my car, but i live in colorado, so it must pass emissions.

thats the only reson i havent bolted up more then a cat back exhaust, id love to get a aftermarket catted h or x pipe, but it just seems so risky to me.........

trial and error i suppose

Rajun_Cajun

The tune has alot to do with it. I think all I need to do is retard the timing a little bit, and I should pass, but Im moving in a month so I said screw it and put my LT's and o/r H on.

5spd GT

A custom camshaft can help you pass emissions

bgchrs2001

well mine being a 91, i dont have to worry about obd2 codes, i just gotta pass the sniffer test on the rollers. last time i went, the guy just threw the hoses on the ground behind the bumper. i ended up passing with 0 CO haha. but i dont think im gonna be that lucky next time.

how much does tuning roughly cost? anyone kno any good tuners in MD?

67mustang302

Old cars that don't have to be smogged FTW!!!

TwoToned306

It cost me 450, with chip and all. For a boosted car it will cost more.