So im stuck on weather i should go witha 400 or 200 cell zzp cat/ downpipe. With the 200 cell cat i would have to tune due to alot less restriction. Or 400 w/o the tune. Any suggestions..

 

depends on your goals of what you want to do with this car..

1. there will be a more aggressive sound between the two
2. yes like u said, the 200 will need to be tuned for

honestly not that much restriction between the two. Each one are still better than the stock. There are many people who are "for" and who are "against" such mods since the stock setup is decent - not great, but decent.
Not sure what the stock cell size is, but I would think it would be about double the range of the ones you are asking about.

again its really up to you, depends on your goals what you want to do with it (ee. super,turbo, exhaust work etc etc)

fyi - I put on a 200 cell, had to get it tuned out. Got it from ZZP for my 2.2 . Real quality piece...but maybe thinking back on it, it may have been overkill lol but o well

 

I just ordered the 400 cell pipe. Got the 400 mainly so I didn't HAVE to tune.

 

I would think if you need to tune for the 200 cell and not the 400, the 400 would be very close to the stock, if not the same, configuration.

Something "double" would be awful high, and would probably cause additional problems as well.

BUT, if you are troubled on what to do, call ZZP and talk with them. They have always provided good reliable info.

JMO

 

i know some cars with 600-800 cell cats coming as stock.
so the lower the number the more "free flowing" the air is which is why it must get tuned so it doesnt throw o2 sensor codes. Whats good now is that ZZP offers an angled o2 bung which is effective at not throwing the code anymore. Im just not sure if its 100%. I would get a tune anyways, makes the car more fun :)

give ZZP a call or send them an email with questions regarding this. I find theyre customer service via email not that great, but maybe thats me.

 

Very rare in 4 cylinder cars. Not saying it is not done, just that it is a last resort for the vehicle manufacturer in an attempt to meet Federal Emissions. And as suggested, this severely inhibits performance.....which the HHR does not experience.

Hell, my Vette has 600 cpi. at 465 HP (436 stock) and no cels.

 

ya i have no idea what the stock cat is..but im just saying ive seen others with that high numbers.

jealous of your vette :p