Serious problems with high-flow cat/downpipe

[Mighty_Mouse]

Seems like everyone with a high-flow cat (test pipe)/downpipe is having problems with them. Complaints about ricey sounding exhaust, check engine lights causing burnt out O2 sensors ($200 each), poor MPG, needing $75 O2 sims that sometimes work, etc.

http://forums.clubrsx.com/showthread.php?s=&threadid=112878

http://forums.clubrsx.com/showthread.php?s=&threadid=110950

http://www.ephatch.com/forum/showthread.php?s=&threadid=24095

Does anyone know if the Random Technologies high-flow cat replacement works better than the one's being sold here and on Ebay?

[Mighty_Mouse]

FYI, these are the one's that I'm talking about: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33629&item=2446797817

[BlackNRedSi]

UTTTO this is no good news! :(
i fer one do not have this, but ide like to know whats goin down with this!

http://images.channeladvisor.com/Sell/SSProfiles/10056063/Images/03%20civic%20si%20hi%20flow%20cat%20II%20x500.jpg

[oogy-boogy]

:eek:
Whoa....I'll def be reading all of this as I was hoping to go that route....

[andy]

Thanks for the links, Mouse.

So far with mine, I didn't really notice any poor MPG (I did on the
highway, but I was also going 90 most of the time). City driving seemed
fine, no real power loss detected.

[Zero Three Si]

Guess I won't be going that route.

[Mugen_EP]

Originally posted by Mighty_Mouse
Seems like everyone with a high-flow cat (test pipe)/downpipe is having problems with them. Complaints about ricey sounding exhaust, check engine lights causing burnt out O2 sensors ($200 each), poor MPG, needing $75 O2 sims that sometimes work, etc.

http://forums.clubrsx.com/showthread.php?s=&threadid=112878

http://forums.clubrsx.com/showthread.php?s=&threadid=110950

http://www.ephatch.com/forum/showthread.php?s=&threadid=24095

Does anyone know if the Random Technologies high-flow cat replacement works better than the one's being sold here and on Ebay?

Here are the answers to your questions.

1) The ricey sound people are "complaining" about is higher air flow, flowing through the mid-pipe. To each his own but to me the sound is not "ricey".

2) CEL's do not cause burnt O2 sensors. With the higher flow of dirty air the O2 sensor will get clogged and may burn faster. You will get a CEL but I have a $25 solution in the works.

3) Poor MPG? Are you serious? Any mod that adds power and increases are flow will generally reduce MPG. Also most people who have a new mod tend to stomp on the gas more.;)

4) Now as for as a $75 sim...again we are working on a $25 solution which looks VERY promising.


hth's

-Tony

[Mighty_Mouse]

[QUOTE]Originally posted by Mugen_EP
[B]Here are the answers to your questions.

2) CEL's do not cause burnt O2 sensors. With the higher flow of dirty air the O2 sensor will get clogged and may burn faster. You will get a CEL but I have a $25 solution in the works.

Wrong. The first O2 sensor is seeing the EXACT same amount of dirty air as before the downpipe. Just because you put a downpipe on doesn't mean that there is more air flowing through it. Think about it for a second. Engines just don't work that way. A larger diameter exhaust decreases backpressure, decreases velocity and keeps flow the same.

3) Poor MPG? Are you serious? Any mod that adds power and increases are flow will generally reduce MPG. Also most people who have a new mod tend to stomp on the gas more.;)

Wrong again. It seems that the CEL is causing the ECU to try and dump more and more fuel over time. This increase in unburnt fuel in the exhaust gas is what's killing the first O2 sensor. If you read the posts above, you'll see that MANY people are having this problem.

Having to spend extra money on an O2 sim that only works in some cases and extra money to replace burnt out O2 sensors doesn't sound too great. It'd be nice to have a good replacement downpipe available, but this one doesn't seem to be it. Maybe the Random Technologies one works better.

[02SilverSiHB]

Originally posted by Mighty_Mouse
[QUOTE]Originally posted by Mugen_EP
[B]Here are the answers to your questions.

2) CEL's do not cause burnt O2 sensors. With the higher flow of dirty air the O2 sensor will get clogged and may burn faster. You will get a CEL but I have a $25 solution in the works.

Wrong. The first O2 sensor is seeing the EXACT same amount of dirty air as before the downpipe. Just because you put a downpipe on doesn't mean that there is more air flowing through it. Think about it for a second. Engines just don't work that way. A larger diameter exhaust decreases backpressure, decreases velocity and keeps flow the same.

3) Poor MPG? Are you serious? Any mod that adds power and increases are flow will generally reduce MPG. Also most people who have a new mod tend to stomp on the gas more.;)

Wrong again. It seems that the CEL is causing the ECU to try and dump more and more fuel over time. This increase in unburnt fuel in the exhaust gas is what's killing the first O2 sensor. If you read the posts above, you'll see that MANY people are having this problem.

Having to spend extra money on an O2 sim that only works in some cases and extra money to replace burnt out O2 sensors doesn't sound too great. It'd be nice to have a good replacement downpipe available, but this one doesn't seem to be it. Maybe the Random Technologies one works better.
I think I agree with you on this. At first I didn't think it was a big deal, but this post got me thinking.
When I put my stock cat back on, I check it out...the thing isn't small that's for sure. It's 2" in diameter and the crap that is supposed to cut down on emissions...doesn't look that bad at all. I think the add power I thought I was getting from the test pipe was just the cooler air...it had just started to get colder here in Texas the day after I put it on.

The ricey sound and the engine light were driving me nuts. I thought about getting an o2 simulator...but why? the amount of money I'd pay for it added onto the test pipe just isn't worth it. I went to the track and hit a 15.52 and a few 15.6's and 15.7's with the test pipe in. I put my stock cat back in and the car felt way better. I'm still hitting 15's even with the stock cat. I hit a 15.51 just this past friday. So to me this mod is worth shit. I'm glad I sold it, I don't miss that damn thing at all!

[02SilverSiHB]

holy shit, another thing. When I put my stock cat back on, I noticed that my o2 sensor..the 2nd one was a tad white.

From reading this one:
http://forums.clubrsx.com/showthread.php?s=&threadid=112878
It sounds like I was going to fry it!
Fuck, I guess mighty is right.

But for what it's worth, I'm sure a test pipe, or a long tube header is great for more serious na mods or boost...for just the i/h/midpipe I have...why bother. I still hit 15.5s