Rep Power: 296

Hey guys, I put in my DC header and HKS-A downpipe last week and I thought everything was fine...but I failed to realize a picture on my dash was covering the CHECK ENGINE light . My car has been running fine but I don't want anything to go wrong. I know its because i have an o2 sensor unplugged - but will this negatively effect the car?

and if not, is there a way to get the light off? its annoying now that i know its there...

 
Rep Power: 432

Why is your O2 sensor not connected?
Go get o2 simulator and put it on if CEL bothers you.

 
Rep Power: 296

where do i get an o2 sim and how does it work? in the HKS-A downpipe there is no spot for the sensor like there is after the cat on the OEM downpipe. thats why its not connected.

My buddy who helped me put on the header/downpipe said he could cut out the bung(i think thats what you call it) in the stock cat and weld it into the HKS-A downpipe where the o2 sensor would plug in...would this help? or would it just show a bad reading and have the CEL on anyways??

 
Rep Power: 0

Just buy an O2 bung from an exhaust shop for $5. You will probably still get a CEL because the secondary cat monitors catalytic converter operation.

 
Rep Power: 296

so no way to get around it?

 
Rep Power: 0

O2 Simulator.

 
Rep Power: 296

i thought the o2 sim would still bring up a CEL

 
Rep Power: 0

Depends how good it is.

 
Rep Power: 0

I have an aftermarket hi-flow cat and there wasnt any spot to put the second 02 sensor, so my buddy weld on a nut and then screw in the 02 sensor. or u can get an 02 stimulator and that will do the job also without welding

 
Rep Power: 282

As long as your car isn't in limp mode don't worry about it.
I have a megan hi-flow cat/resonator and when the stock cat was removed the o2 sensor was stuck in the cat. The person who installed it said it would be ok.I still have a CEL but it isn't bothering me.Just don't mess with the first o2 sensor.

 
Rep Power: 333

^agreed. first o2 sensor (primary: the one before the downpipe and on header) is a must because i THINK it has to do with something reading how much fuel and air the ecu reading?

but a decent o2 sim. may solve your problem depending on your pipes and location.

 
Rep Power: 0

If the CEL is on, the car is not running like it should, you should have got the random tech cat... I know it costs more but it has spots for both o2 sensors and it doesnt cause a CEL, I used to have the HKS-A pipe and had nothing but problems so I sold it.... Now i have the random tech cat and couldn't be happier...

 
Rep Power: 296

not running like it should how? it seems more responsive now with the HKS-A downpipe, but maybe its in my head?? i dunno - I didn't even know the CEL was on because I had a pic of my girl on the gauges, didn't know the light was on til i took a corner hard and the pic fell. lol

how does the random tech feel/sound different from the HKS-A?