Installed the hiflow ebay cat (Straight Pipe) and reset the ECU. It was like $40. I've had it on for week. First impression, I like the tone. Similar to a Z when combined with a SS Y-Pipe, 2.5" B-Pipe, and stock can. Performance wise, butt dyno can really notice any difference. However, today my SES light came on! Went to Autozone, and it said, something like a P2040...low cat efficiency...past capable threshhold. Anyway, light is still on. Need help. Wait and see if it goes off or put factory cat back on. Can this damage the engine in any way? Has this happened to anyone else? Thanks for the help.

 

not sure why it is. i gutted my cat and installed a y-pipe and i have had no codes. try resetting your ecu again and see if it comes back

 

i have a straight pipe and got the same thing. basically the O2 sensor behind the cat sends a signal to the ECU which checks that with the signal from the sensor in front of the cat. the ECU compares the two values to make sure the cat is working. when you have a straight pipe then the ECU gets the same value from both sensors which trips the light.
bottom line...the light is simply letting you know something is wrong with the cat (well duh..there isnt one!!) but the ECU does not do anything else when it has that code (ie change fuel mixture etc)

see my sig for the video of my exhaust...i love it

 

So you still have an SES light? So the fuel mixture etc won't be affected? What do you think fellow Okie, leave it or switch back? So obviously I'm not the only one to have this issue. That's reassuring. Thanks.

 

i disconnected the battery a week ago and it hasnt come back on. the only thing the ECU does is send out a signal to turn the SES light on...nothing else.
leave it..i am

 

Whatup Jason. I think I am going to order the Budget ypipe tomorrow and then get their test pipe as well which they only charge like 15 bucks for when buying another component. I know Nissan is putting on my brand new cat tomorrow to fix the P0420 code and I will probably just take that one off and hold onto it if I ever decide to sell it. I am also thinking about gettin the O2 simulator to solve the SES light issue.

 

thats a good idea to save a brand new cat for when you sell the car. but now you are gonna get the P0420 code again

 

I think this has turned into a OK thread. I'll disconnect again tonight and see what happens. I'm not too worried and dig the exhaust tone. We need to do a meet at Thunder Valley sometime in the spring.

 

well since we dont have inspections...
a meet would be cool..just a LONG @SS trip for me

 

Disconnected + reconnected battery = no SES light for now. Time will tell. Last time it took a week after the install before it showed up...can't be that big of a deal. Jason just find somewhere close to go TDY to...

 

yeah mine took a week to come on to.
if i go TDY ill fly. i still have friends and family in Tulsa and OKC...but screw driving. last time i did that it took me 22 hours with only stops for gas i just need to PCS back to Tinker

 

I am unsure if it will still show up if I run the O2 simulator. If I can't seem to solve that problem, I will most likely just kill the straight pipe idea and run the ypipe alone.

 

I have the high flow cat and i have the SES light too. I did reset the ECU, but afer like 700 miles it went back on. i'll put in my old cat next week just to check if that is the issue with SES.