Does anyone have HFCs installed on an HKS exhaust? I'm looking at a used coupe that currently has an HKS with test pipes installed, but I need to throw some cats on there to pass inspection.

Been on the phone all day and it seems like as long as I install some cats, I should be fine for inspection. Can I directly replace the test pipes with high flow cats and be done with it?

If so, does anyone have any input as to which brands are compatible with the HKS unit? From what I've read, the Berks HFC is for sure, but unless I'm mistaken, it makes it much louder, which I'm not exactly looking for right now. If that's my only option though, I'd be willing to do it.

Thanks a lot.

 

Bump

 

im pretty sure you can put any test pipe, hfc on. and i will have no problom fitting.

 

Thanks for the input, and the bump

I'd love to hear from someone with first hand experience as well if anyone has any.

Another quick question here. Removing the test pipes and installing the HFC's shouldn't be too difficult, right? Do-able with jackstands?

 

I have the HKS exhaust on my coupe. I used to have Crawford HFC's but I put the stock ones back on. Having HFC's will make your exhaust louder but not as loud if you are running test pipes. The Crawfod HFC's look similar to stock. And changing out your cats is definitely not a jack stand job. You'll need to put the car on a lift. Just hollah if you got anymore questions.

 

Thanks a lot man. Did you run into any problems with your Crawford's? Just curious as to why you swapped them out.

Also, I've been watching this video. Looks like he has it on blocks. I've never gone through the process first hand, but I'd assume I could manage with ramps if they're a similar height to those blocks?

 

One of my Crawford HFC's started to come apart on the inside. I guess if you put it up as high as it is in the video it's doable. But most guys would probably just do it on a lift.

 

A lift would be great, but unfortunately I don't have access to one.

You didn't have any problems passing emissions/inspection with your Crawfords did you?

And correct me if I'm wrong, but the HKS system has the oxygen sensors on it, right?

 

My coupe is an 06 so I haven't had to do the sniffer test yet. I put my stock cats back on about two years ago. I think guys have still passed emissions with HFC's though. The HKS exhaust system does not have any place to put the sensors on it.

 

i did my pipes on jack stands, its deff a 2 man job getting the stock cats off. your gonna need some pb blaster and a 20" extention to come in from the top to get them upper bolts off the cats. PITA

 

This may be a stupid question, but if the HKS system does not have a place to put the sensors, how do people pass inspections?

Getting the extensions and a helping hand shouldn't be an issue. Do you have a rough estimate of how long it took you to do it? I think I'd rather have it be a PITA and free, than taking it somewhere and having to pay to have it done.

 

total it took about 4 hours, that was with breaks and running back and forth to pepboys.

 

@ Th611 are you talking about the 02 sensors that screw into the cats?

 

Ah, that makes sense then. Yeah those are the sensors I'm talking about. I didn't realize they screwed into the cats.

So those who are running test pipes just remove the sensors completely? And throw them back on when they install cats for inspection?

 

For guys running test pipes they still screw the sensor into the test pipe. I believe they are just more prone to having a CEL come on. So some guys put on non-foulers to prevent this.