So I'm looking to buy a new Strup header but want to know if the defouler is absoultely necessary. Everyone says to use one, but another user on another forum told me that the Strup won't throw a CEL, and in fact it messes up the car's A/F ratio and what not when using a defouler. What's the truth?

 

Bump...

 

i run a test pipe and use a defouler, don't know about it messing up a/f ratios though because i've never had any problems. Any aftermarket header that eliminates the cat will make the car throw a CEL.

 

You will get a CEL without one. I don't know how much it will throw off you AFR because I never used one, but you can always circumvent this whole situation by getting Flashpro and eliminating the 2nd O2 sensor.

 

i dont recommend you get a strup. i would get a dc or even kiddracing header.

 

Any race header is gonna throw a CEL. If the car throws one for the secondary O2 sensor because of that RH and you DONT get a defouler to get rid of it, then if the car has another problem that causes a CEL....you won't know the problem is there because the CEL has already been tripped by the race header.

If you're lookin to keep it cheap then buy a DCRH and the Blox defouler and save yourself the trouble.

Using a defouler does NOT mess up the AF ratio. The A/F ratio is basically monitored through the primary O2 sensor......the one located before the cat. The defouler is just a simple little part that the secondary O2 sensor screws into so that there is less exhaust gases reaching the secondary sensor. It basically tricks the ECU ino thinking there is still a functioning catalytic converter.

 

jesus christ, here goes my infamous post with the same link, for the 7th time.

this is what you need. without this, you will throw a cel regardless of what you do on the stock ecu calibration (ha i updated my sh*t)

http://www.jhpusa.com/store/pc/viewP...idproduct=2952

 

x2. the secondary o2 doesn't affect the a/f ratio. if you don't use a defouler the only problem you'll have is that the cel will be on, so no, using a defouler isn't absolutely necessary.

 

Really? Isn't Strup the same design as DC? I've heard nothing but good reviews on the header at 8thgen.

 

"Another Strup flex pipe leak" is very common to see over there in the bolt-on section these days. They are fixing it for free but that means downtime for your ride because you have to send it in to be replaced. The DC flex pipes have been holding up better, but in that price range I would just grab up a Kiddracing, or go ahead and pull the trigger on a s2.

As for the defouler, they are like 6 bucks man common. To skimp here is silly, and many exhaust shops have them on hand. Our cars play nicer with the angled ones, but the regular ole straight ones have been working too so why not?

Now if you plan to go with FlashPro then it's pointless, because you can disable the secondary O2 sensor all together, and never get a CEL from exhaust again. The secondary O2 is just checking to see if the cat is working anyhow. Then to cap it all off, CEL=failed inspection in pretty much every state.

 

I have a Vibrant RH without a cat and ran into the CEL with the normal short defouler.
I then bought the angled strup defouler and again threw a CEL. In time I'm going to get the flash pro, but until then, any suggestions?

 

Clear the code and check the defouler. It may be that the hole is too large in the angled one, letting too much exhaust at the sensor. If it's fine, then you will just have to keep clearing the code til you get the flashpro.

 

i just got a race header and still have a stock CAT. my CEL light came on after 300 miles.
can i still use the defouler for the stock cat????

 

^stock cat on race header? you can't do that

 

haha i was thinking the same thing; a race header replaces the cat with either a straight pipe or a high-flow cat.

 

Nice. But the site says that it's for a '90-'00 Teg. Will it still work for an '07 Civic LX? TIA