Foxbody 302 to 331 stroker emissions

[Blooddiamond91]

I have a 91 fox convertible with gt40 intake and heads setup. Does anyone know if doing a 331 stroker would affect emissions especially in Colorado where emissions is getting stricter.

 

[Noobz347]

I have a 91 fox convertible with gt40 intake and heads setup. Does anyone know if doing a 331 stroker would affect emissions especially in Colorado where emissions is getting stricter.

That depends wholly on your smog equipment and cam.

If you're building a 331 then it's in your best interest to choose a smog friendly cam or better yet... Purchase custom cam for your build and emphasize [smog legal] as the priority.

Done correctly, nobody would know the 331 from the stock block (although aluminum heads are a dead giveaway).

 

[Noobz347]

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[AeroCoupe]

Another option is to put a tune into it strictly for emissions testing. I had one when I lived in Texas and the 331 passed no issues.

Forgot to mention this was with zero of the stock emissions crap. Swapped the X pipe out for the X pipe with Walker universal cats and went out and got them good an hot before I backed the car on the rollers. Texas does not do a visual under the hood and Oklahoma does not do inspections so I haven't had to put the catted X pipe since I moved back home.

 

[nickyb]

I agree about getting a emission friendly tune, shouldn't have a problem passing even in the rockies.

 

[Blooddiamond91]

Now for a tune, how do you tune the A9P? I’ve seen the bama tune and chip that connects to the ecu. I know you don’t have to throw a tune at a hci upgrade but what’s the best tuner as far as the A9P?

 

[nickyb]

You can use a mega squirt plug n play to tune for emissions, or power,or mileage.
Don't believe you can tune a stock ecc4 without something like a quarter horse.

 

[AeroCoupe]

SCT switch chip and a dyno session is how I did mine. Bought and will be switching to the MSPnP down the road as finding a tuner where I live now is impossible.

 

[2000xp8]

For curiosity's sake I looked up Colorado. Looks like a mixed bag of senseless confusion. They probably cause more emissions than they prevent testing cars older than 1996. NJ gave up it years ago, the math didn't make sense.

With that said, I've seen all kinds of cars pass (when they used to test) as long as they had all the correct parts in place. For the most part. Cats alone did the trick and even guys with no cats and vortechs passed.

 

[limp]

For curiosity's sake I looked up Colorado. Looks like a mixed bag of senseless confusion. They probably cause more emissions than they prevent testing cars older than 1996.

Colorado has be Californicated so that would make sense

 

[Mustang5L5]

Colorado does an actual sniffer test?

How many states still do that?

 

[Blooddiamond91]

Colorado does an actual sniffer test?

How many states still do that?

yes sniffer and inspection.