Check engine light

[02firebird]

I put a high flow cat on the other day, and now my service engine light is on. What do I need to do to get it off?

[02firebird]

Re: Check engine light

I know this is illegal to put on a street car, but it sounds like it would work

http://fasttoys.net/shop/product_inf...e1e9f25ce4773e

[ssms5411]

Re: Check engine light

People use that or just tune them out with Hptuners. Not uncommon.

[Docta]

Re: Check engine light

I've got a sim... works magic.

[02firebird]

Re: Check engine light

Cool thanks, I'll get the sim, much cheaper solution. I'm assuming you still pass inspection with the sim? Oh, and is there any effect on the car if I don't get the sim in the next couple weeks?

[Docta]

Re: Check engine light

Not sure about inspections... but the only effect you're going to notice is gas mileage. And it will run lean/rich. And you can find a sim cheaper than that, jus'sayin.

[timthescarred]

Re: Check engine light

I may be wrong on this, but as I understand it, our cars only use the downstream "after the cat" O2 to determine if the CAT is working or not, lean/rich is solely controlled based on the O2 sensors before the CAT.

As far as inspection goes it varies based on where you live, if they put a sniffer on your car it may not pass at all with the high-flow, just depending on how much they are checking for. if they do a visual inspection and notice the sim they may fail you, if they just check for DTC's you should be fine.

[02firebird]

Re: Check engine light

I think I'm just going to go ahead and get a dyno tune instead. I have a few things done on the car and I would rather make sure I pass inspection and get everything done right.

[ssms5411]

Re: Check engine light

Tunning is your best bet.

[Hib Halverson]

Re: Check engine light

I put a high flow cat on the other day, and now my service engine light is on. What do I need to do to get it off?

How do you know the code requesting the MIL was caused by the change to a high-flow cat?

[02firebird]

Re: Check engine light

I had my codes scanned and got this code, P0420. Which is the oxygen sensor that monitors the cat saying that it is defective or bad.

[Docta]

Re: Check engine light

420 is the post-cat O2 sensor... it's probably the single most common OBD code. The sensor is bad, not your cat most likely. I mean it could be your cat, but the sensor is a ton cheaper and easier to replace.

[Rob Bell]

Re: Check engine light

Good point, I would think that a properly working hi-flow cat should still enable the car to pass an emission check, and also not set off the post-cat sensor. If it cannot do that, they shouldn't be selling it.

[02firebird]

Re: Check engine light

I talked to the shop that put it on, and they agreed to buy and replace the O2 sensor for free. So hopefully that's the problem.

[whitdog54]

Re: Check engine light

^do you have a hi flow cat? Have them move the 02 bung further down the exhaust towards the axle