[Z06] Removed Cats/check engine light on

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Sep 21, 2004 | 08:33 AM

bldme2

Thread Starter

Cruising

Joined: Jun 2003

Posts: 13

Likes: 0

From: Plainfield IL

Removed Cats/check engine light on

I removed my cats recently, and after a few starts the check engine light came on---dealer reset it--it showed problem with the cats which is understandable. Is this always the case---will the light continually be on or can I do something to keep it off? Also, seems to be running rich now---is this normal? Do I need to get it re-tuned? I run it on the track at Road America so I really want to make sure that I don't have any problems. If I do need to get it re-tuned---any suggestions for a good shop in Chicago area? Thanks for your help!

Sep 21, 2004 | 08:36 AM

AFVETTE

Team Owner

Joined: Sep 1999

Posts: 20,054

Likes: 44

From: Swansea IL

Did you also install 02 (Oxygen Sensor) sims? If not that's your problem. And yes you will need to be re-tuned. FLP can LS1Edit tune your car.

I'm not sure why folks need the extra 5 or so HP removing the cat's offer. Maybe I'm getting "greener" as I get older.

Tom

Sep 21, 2004 | 08:39 AM

KCZ

Instructor

Joined: May 2003

Posts: 154

Likes: 0

From: Kansas City Kansas

Need to install the O2 sensor simulators that plug into the harness just behind the motor. These replace the harness that runs to the rear O2 sensors and emulates the cats to the computer.

You can then plug the sensor bungs in the rear. I used a couple of oil drain plugs to seal off these connections.

You can get the O2 simulators from several of the dealers on the left.

Steve

Sep 21, 2004 | 10:09 AM

CYA-Vett

Melting Slicks

Joined: Nov 2002

Posts: 3,398

Likes: 2

From: Allentown PA

Quote:

Originally Posted by AFVETTE

Along with the 5 or so HP, removal of cats moves the exhaust drone up about 1000 rpm which is necessary on the highway with aftermarket exhaust/headers if you want to hold a conversation. And 5 HP is is noticeable if your a racer and have a racing problem, like me.

Sep 21, 2004 | 01:05 PM

RussBt

Le Mans Master

Joined: Jun 2001

Posts: 7,331

Likes: 518

From: Admit Nothing, Deny Everything, Make Counter Accusations.

The light is coming on because your rear O2 sensors are reporting that the cats are not working. You can disable the rear O2 sensor diagnostic with LS1Edit. If you plan on getting the car tuned then you do not need the O2 sims.

Sep 23, 2004 | 09:34 PM

bldme2

Thread Starter

Cruising

Joined: Jun 2003

Posts: 13

Likes: 0

From: Plainfield IL

WHo and where is FLP? I appreciate the heads up on this---it's not only the horsepower benefit but also the car should run a little cooler out on the track. Thanks again!