If I Take Off Cat Convs. And Put Test Pipes On Will "cel"

[IBCOOL]

If I take the catalytic converters off of my 96 NSX and put on the dali test pipes with my comptech headers and comptech exhaust will the check engine light come on? If so, is there a device that I can order to make it not come on because I notice that my gas mileage goes way down when the check engine light is on.
Also, my car is really quiet as is. Will it be noticeably louder with the test pipes, headers, and comptech exhaust setup that I will be running? Thanks

 

[docjohn]

I have a 96 and have run without cats for years(At the track only):wink: had o2 sensor cels 1-2 per yr corrected by o2 sensor replacement but who knows if the absence of cats had anything to do with that.Otherwise the 96 ecu is more tolerant than 02 and up with test pipes.You should be ok.Trust me though depending on the type of exhaust you use you will get noticed because of the loud factor.

 

[Frank Spano]

I have had my comptech test pipes on for 6 years and not once has the check engine light come on. Frank

 

[davidf]

So what are anti-foulers I here about all the time with test pipes?

 

[rasir_x]

I get it CEL once a year and the acura dealer just replaces the O2 sensor since its under waranty

 

[DPG]

These are more than likely 91 through 94's these are OBD1 and do not have a secondary O2. The primary O2 is before the cats so there is no problem. The 95 up cars have OBD2 and have a set of O2's behind the cats. These are to make sure that the cats are working properly. that is why the light will come on if you remove the cats.

So what are anti-foulers I here about all the time with test pipes?

 

[Slipstream]

If you do get CEL's, you can prevent them easily by picking up a CEL eliminator. It's a small electronic device that fools the stock ECU. These are only good for the secondary O2 sensor. you dont want to mess with the primary or the car will not meter fuel properly.

 

[Larry Bastanza]

These are more than likely 91 through 95's these are OBD1 and do not have a secondary O2.

1991-94 are OBDI

95+ are OBDII

 

[davidf]

So to claify, if I install aftermarket exhaust and test pipes, do I need anything else? Will the 02 sensor be ok with that? Thanks.

 

[DPG]

Corrected

 

[DPG]

If you do get CEL's, you can prevent them easily by picking up a CEL eliminator. It's a small electronic device that fools the stock ECU. These are only good for the secondary O2 sensor. you dont want to mess with the primary or the car will not meter fuel properly.

Do you know the voltage that the secondary O2's run? I have been wondering this for a while now. (not that I have investigated this much)

 

[TURBO2GO]

I have the 02 simulators on my car, and it has not solved the problem fully. You will absoluetly get a cel if you do nothing. If you get the simulators, which is basically a metal thingie that pulls the sensor out another 2 inches, you may or may not get CELs.

Frankly I am not even that fond of the idea of running without cats and polluting... but I have other issues right now as my car is an 05 OBDII, my exhaust is an NA1, and my 02 sensors are from a Honda Fit. I also have a CTSC. I get a cel once a week now.

P0136 and P0137. It used to be just "02 sensor 2, bank 1". Now its the 02 sensor code (P0137), plus "bad 02 sensor circuit, sensor 2 bank 1" (P0136). I am not sure if the consecutive resets of the the P0137 02 sensor code are triggering the P0136 sensor CIRCUIT code or if I have two seperate issues. Maybe someone can shed some light for me.

 

[Matt_337]

So to claify, if I install aftermarket exhaust and test pipes, do I need anything else? Will the 02 sensor be ok with that? Thanks.

David
You should be fine with your 91 (you won't need the 02 simulator)

 

[davidf]

Thanks Matt.

 

[IBCOOL]

I went ahead and put the JGTC parallel exit exhaust I had in storage on my car yesterday instead of putting the test pipes on with the Comptech exhaust that I had on my car.

I really love the way the JGTC "GROWLS." Plus I do not have to worry about the CEL coming on and I will not have to remove the test pipes every year to pass smog. I did have to put some of that spark plug wire insulation on the wires for the O2 sensors to protect them from the extreme heat put out by the JGTC exhaust and its close proximity to those o2 sensor wires when installed.

I had installed the JGTC parallel exit exhaust 3 weeks ago, and after driving home from the muffler shop I smelled plastic burning. My CEL light came on. I took the car to Acura and they showed me where the heat from the JGTC exhaust had melted the wire leading to the o2 sensor. That cost $150 to fix, ( the Acura tech fixed the burned wires and re-installed the Comptech exhaust) so, I figured I had better put that insulation on the wires or else they would burn again. Has anyone ever experienced this problem of burning the o2 sensor wires on a 96 NSX when installing the JGTC parallel exit exhaust?

I am going to go ahead and sell the Comptech exhaust that I have as I have an OEM exhuast in storage also( too many exhausts, too few NSXs).

The Comptech exhaust must be all stainless as it is shiny and bright and looks new. The guy I bought the car from says the Comptech exhaust had a lifetime warranty and is pretty much bulletproof. Is there any truth to that?

So my setup now is the Comptech headers and Comptech teflon airbox, JGTC parallel exit exhaust, Koni adjustable shocks, TSW Montage wheels( I get compliments on these wheels every day), JDM Honda dark rear tailights with "H" emblem in rear center tailight piece and black "H" on front of car.

I also have the sheepskin seatcovers,which, if they would stay in their fixed position, would be a joy, but, seem to be more of a pain in the behind.

Thanks to everyone for their input. It led me to not go with the test pipes and to go with a different exhaust. If I understood the comments correctly, if I had an earlier model with only the (2) o2 sensors this "CEL" light problem would not have been an issue when installing the test pipes. Thanks again!

 

[IBCOOL]

I made a mistake in my last post when I said I had a Comptech Teflon airbox. It should have read Comptech Carbon fiber airbox. My Apologies. Thank you.

 

[docjohn]

Teflon might be better,no air molecules will stick to the sides!:smile:

 

[SWIFTVISION]

I have the 02 simulators on my car, and it has not solved the problem fully. You will absoluetly get a cel if you do nothing. If you get the simulators, which is basically a metal thingie that pulls the sensor out another 2 inches, you may or may not get CELs.

Frankly I am not even that fond of the idea of running without cats and polluting... but I have other issues right now as my car is an 05 OBDII, my exhaust is an NA1, and my 02 sensors are from a Honda Fit. I also have a CTSC. I get a cel once a week now.

P0136 and P0137. It used to be just "02 sensor 2, bank 1". Now its the 02 sensor code (P0137), plus "bad 02 sensor circuit, sensor 2 bank 1" (P0136). I am not sure if the consecutive resets of the the P0137 02 sensor code are triggering the P0136 sensor CIRCUIT code or if I have two seperate issues. Maybe someone can shed some light for me.

A couple things....

#1 I sell electonic 02 sensor simulators made just for the NSX...you will NEVER get a CEL on again from having straight pipes. You need these if you want to run striaght pipes on 95-05 cars. PM me if anyone needs a pair.

#2 About polluting....even with headers, intake, exhaust and straight pipes I just barely failed a smog test...so overall the NSX is pretty clean running.

 

[808NA1]

I have the 02 simulators on my car, and it has not solved the problem fully. You will absoluetly get a cel if you do nothing. If you get the simulators, which is basically a metal thingie that pulls the sensor out another 2 inches, you may or may not get CELs.

Frankly I am not even that fond of the idea of running without cats and polluting... but I have other issues right now as my car is an 05 OBDII, my exhaust is an NA1, and my 02 sensors are from a Honda Fit. I also have a CTSC. I get a cel once a week now.

This is not personal experience with NSX's, but I have known this to work with other Hondas.

I am assuming you have a couple spark plug defoulers on your secondary O2 sensors. I don't know if there is enough room, but you could try adding another defouler to pull the O2 further away from the exhaust stream.

Or you could try this... As ghetto as it may seem, but it pretty much won't cost you anything, except your time. Try taking the secondary O2's completely out of the test pipes and secure them up somewhere and plug the O2 bung. I know, I know, it sounds lame and ghetto, but just try it.