Here's my take on things.

If your gonna get a CEL with HFC's, whether it be after 200 miles or 3k miles, might as well just get test pipes and maximize power output. It wouldn't make any sense considering the price of HFC's, unless you live in a highly regulated state like CA.

As someone previously stated, these things just come with the territory of modding. The light never bothered me but I guess I'm just so used to it that I never notice it anymore.

I've done a lot of modding, including forced induction and I've never tolerated the light. But I do agree you may as well just get the test pipes anyway.

My old Trans Am has had a light for the past 20k miles or so. It's complaining about the EGR, might be because I completely removed the EGR system from the car. :icon17: It comes back every time I reset it, so I gave up. My programmer (a DiabloSport unit) is supposed to be able to permanently suppress it, but I never got that to work. Oh well :)

I had an APS turbo'd 350. I was only concerned when that light wasn't on...:rofl2:

There are other reasons one might want to go with HFCs. Test pipes tend to have more rasp (even the resonated ones). And when I ran test pipes on my 350, the rear valance regularly got coated with a layer of black soot. So this time around I decided to go with HFCs. I haven't gotten a CEL with the HFCs, btw. At this point, I don't think a single person with a 370 has gotten a CEL from the Berk HFCs. All this talk about a fix is merely hypothetical at this point, i.e., what to do if and when we get a CEL. (I'm also the guy who said that CELs just come w/ the territory.)

the test pipes only have a rasp for a slight moment (2600-2900rpm) under medium acceleration. but i loveeeeeeeeeeeeee the sound of them. super aggressive and almost like an exotic at the higher rpms. am i the only one with test pipes on the 370 here? as for my service engine light, i will try that ss wool this weekend maybe. if that doesnt work i will do the other fix when i have time (probably a couple of weeks). the light hardly bothers me anymore. the sound and performance of the pipes far outweighs the annoyance of the light.

Per UPREV this is correct. The rear ones only verify the cats are working and that is all. The car runs no different and these can be turned off in the ECU tuning.

Rasp doesn't bother me either, personally. I'm just pointing out that it does bother some people, so that's a legitimate reason to go with HFCs vs. test pipes. What ever happened to the dyno you were going to get on the Berk test pipes per your other thread? http://www.the370z.com/intake-exhaus...mpression.html

I want to see numbers -- numbers are more meaningful than sound to me.

the dyno that i will go to is a mustang dyno, so maybe we can compare my run with RCZs baseline (yes diff dyno/diff day). i will update that thread once i do it

Cool! Thx man.

Test Pipes will cause the light to come on and there will be not much you can do to not prevent the light coming on with those. With HFCs though you have a chance of preventing it with the methods above. Also less rasp, less smell with HFCs.

Not sure why Stillen (maybe due to lack of experience as they don't specialize in ecu tuning) keeps saying the o2's behind the cats that do the fuel adjustments when it's the front o2's that do the fuel/air adjustments as they need a reading before they hit the cats. UPREV has already disabled these o2s on several cars with no issues.

nice. we got a guy on the inside. haha. so how do u propose to fix the code that the computer is spitting Jesse? uprev?

^^ you definitely have more knowledge than i do. I completely agree that only the first 02 have an effect of fuel. i think NismoZ brought that point up too

I think some of your guys are misinterpreting Stillen, this is why he edited to add that they specifically affect CEL. The rear only checks for cat deficiency. The fronts control fuel under load, aka when it matters. You can drive the car with the rear o2 sensors completely unplugged and it wont affect anything. Its the CEL's that you have to worry about if you don't like lights on the dash like me.

Right, he was responding to my comment about O2 sims. While the rears are only for emissions purposes (CEL), they can't be fooled with simple sims, because the ECU is actually looking for them to respond to small changes in fuel delivery. Killing the rear O2 without a CEL would require either a very advanced O2 sim/replacement that bases its outputs on what the car is actually doing (doesn't exist), or reflashing the ECU to ignore them.