Crawford Hi-Flo Cat's?
 

What type of gain's are expected with a stock exhaust?

Sorry if this has been answered before.

A buddy came by this evening. Had his Hi-Flow Cats installed, and his MIL (CEL) is lit. I tried to pull a code with my OBD II reader, but it didn't read anything. Pressing reset didn't clear the light.

Also tried a 'Pedal Method' ECU reset, but I couldn't get it to work for me this time, so I'm not sure if it would have cleared the light or not.

Any ideas about why the MIL is lit and no code registers? We thank you in advance. :)

Gordon,

Which hi-flow cats did your friend install?

2 to 1 odds are that one of the Oxygen Sensors were damaged during the install. Same thing happened to catatafish last year around this time. If you're not super careful with the removal and reinstall of the O2 sensor they can be very easily damaged. Worst case your friend is out ~$130 or so. Keep us informed as to what the problem was.

5-10rwhp by themselves. Add a Crawford plenum and a z-tube and you'll be closer to 20rwhp. (I've actually dynoed my car to show these gains) Throw in a set of Crawford Headers and my guess is that you'll be close to 40rwhp. I'll have an actual dyno today to get a real number, the ~40rwhp is an educated guess at this point.

Just installed the Crawford cats today...(Marv Albert)...YEEEEESSSS!! Too early to tell on power, but everyone in the shop kept commenting on how nice and how well made they are. Up here in Delaware the guy even knows of Doug Crawford! Sounds great, deep mean growl, no farty or tin-can sound. Will update with performance critique.

They were the Crawfords.

Thanks neff. I thought this would still throw a code however? We'll see what he finds out.

Yeah, unfortunately its one of my O2 sensors, bank 2,which is the passenger side. Hopefully all will be well once this is replaced. Also had to bend the heat shield on the driver's side as this would rub against the frame when accelerating.

why is that only the driver's side heat shield that needs to be bent? what happne to the passenger side?

There's more clearance on the passenger side, so no rubbing occurs.

Actually the clearance is about the same, but when the engine is under torque it twists clockwise (from the perspective of sitting in the drivers seat) in it's mounts which in turn forces the drivers side cat to the left a little and it rubs on the frame.

Gordgee,

In the last week I've learned a bit more about our cars. (Quite a bit actually). You're right, a broken or damaged O2 sensor would definitely throw a recognizable code with your OBD-II scanner.

One important thing, does your friend have a car with a 10/03 build date or later? If so, he has an ECU that connects to a 6 wire O2 Sensor (instead of the 4 wire O2 sensor). The 10/03 model cars or later can't be run with straight pipes w/o throwing a CEL. I've read that stillen sells a ~$50 box to trick the ECU into not throwing the code, but if your buddie has a 10/03 build date or later this very well could be his problem. Maybe check Stillen's website and do a little reading on my350z.com to see if this could be the issue. Good Luck. Make sure to keep us informed.

i also had a rubbing issue on driver side. still has some rattle under hard acceleration, but not as much as it used to be after few adjustment. there is no CEL(MIL) on mine. it sounds great, and seems i got better throttle response. i haven't dynoed my car, but i could notice the difference after i drive my buddy's stock 04 6 speed.

Curious that your not throwing any code? I have an 04 and the high flow cat installer did not completely snap in O2 sensor eletrical connector back into place-it looked like it was plugged in but was'nt and resulted in a CEL..After I snapped it back into place and reset the code using my scan tool..No More CEL..pushing 3K miles fingers crossed.... ;)


If all else fails try this--this was my contigency plan:

http://www.o2sensorsimulator.com/


Im looking forward to any other suggestions for the driver side cat rub during hard acceleration? Its about 90% gone but not..Im willing to try anything? One exaust guy looked at it and suggested an L bracket similar to the stock one but said it may not work because the motor and brackets will still move in the same direction and have the same result? Another guy said remove the heat shield--Im no expert but that sounds like a terrible idea?

I had no issue's with the Crawford install on my 6MT Coupe. The Cats are very well made, the perform and sound great. A great mod.

Lou