gilroy222

Hey guys,

I'm normally over in the LS4 section but most everybody there is from the U.S. or still have their normal Cats so this doesn't really apply to them.

Im debating with the idea of getting a catless downpipe for my GXP. Lew says he can tune it so there's no codes showing and can tune the engine to still run at the right mixture and such.

I normally wouldn't do it but I got my 4-cylinder mode tuned out so I lost some mileage, but apparently with no Cats he turns off the Cat OverTemp Sensor (engine dumps fuel into the mixture to cool the Cat before it gets too hot) and it can actually give u a big increase... so I've heard.

So I'm just wondering if anyone has straight piped their cars and still passed the OBD II tests they do now instead of pipe sniffing.

transamtom

iTrader: (8)

You do know they don't do the tailpipe testing anymore right?

They use the ALDL link under the dash and look at the codes and system monitors.

A good tune gets you your pass.

gilroy222

Yes I realise they don't pipe sniff anymore. That was the reason for my question lol...

Thanks for the answer though. I may go ahead with it then.

LETZRIDE

iTrader: (6)

Hopefully this answers your question.

All you need is your readiness monitors to show ready...

How to tune your readiness monitors to ready

gilroy222

Thanks very much.

Do they still look under the car at the cat itself?

LETZRIDE

iTrader: (6)

nope.

Ghostintheshell

That's a fast N/A v6 letzride!

LETZRIDE

iTrader: (6)

Thanks! she's parted out now unfortunately

jrwilliams95z28

they do still do the sniff test but only on obd1 cars

LETZRIDE

iTrader: (6)

no on OBD II cars as well until 98, only 98+ is OBD tested

jrwilliams95z28

which is what I said, they do still do the sniff test, only on obd1 cars... which means 95 and older.

1997trans-am

iTrader: (2)

97 or older

jrwilliams95z28

No OBD2 is 1996 and newer, hence why 1995 and older are OBD1 and require the sniffer test still.

1997trans-am

iTrader: (2)

I have a 97.... They did a sniff test last month..

Mine is actually an LS swap with a 2001 Silverado 5.3 along with the entire harness and OBD2. They would not let me put it on the scanner.


Here is a link:
https://www.ontario.ca/environment-a...ions-test-done

LETZRIDE

iTrader: (6)

Yes but you're misunderstanding 96 and 97 are OBD II and still require a sniff test, not the OBDII test...I had a huge argument with the ministry regarding my 96 and why it couldn't be tested under the new test...

mk2vr6t

i have no cats, cam, long tubes...

tuned w/ HPTuners - no CEL - all sensors 'ready' - passed e-test no problem.

WS6wanted

Thats awesome

gilroy222

Alright thanks guys. I may go ahead with it then