Can 02 sims help me pass emissions?

**GottaHaveLS1** · 06-06-2007, 12:03 PM

I have two bad 02 sensors that are throwing codes. I want to get my headers & y pipe but can't afford it yet. I have emissions coming up soon and i know they will just scan the computer. if i replace the bad 02's with 02 sims, there should be no codes right? all i have is the magnaflow cb, so i think i should pass.

Also, autozone scanned my computer and a code came up saying soemthin like: "1-4 shift selenoid malfunction", this is cuz i did !CAGS. so i'm throwing a code from having a skipshift but i should still pass emissions if my 02's are replaced right????

**SSpdDmon** · 06-06-2007, 12:22 PM

What did you do to kill the CAGS? If you can plug it back in just for inspection, then you might as well. Only takes a few minutes.

If they to a sniffer test, then sims may not save you. Either your sensors or your cats are going bad (we are talking about the rears, right?). Sims will kill the code since they trick the PCM. But if the cats are bad and they sniff the exhaust, then you may not pass.

**Mr. Luos** · 06-06-2007, 12:36 PM

If your SES light is on....you won't pass.

**Tonik** · 06-06-2007, 07:47 PM

Originally Posted by Mr. Luos

If your SES light is on....you won't pass.

+1

Certified here in TX... If your light is on I couldn't pass you if I wanted... Computer wont let me.

**sunsetorangess** · 06-07-2007, 08:27 AM

I passed with 02 sims in the rear, although you cannot use them in the front. What codes are you throwing? If your emission systems arent running or throwing codes, they will not pass you because they plug it into a computer and it does its thing.
J

**GottaHaveLS1** · 06-08-2007, 12:40 PM

i'm not sure which codes i'm throwing, but i might just go get it scanned again. The rear 02's are the bad ones.

If I take care of the skip shift and get 02 sims to get rid of the bad 02 codes, then hopefully my SES light won't be on. I should pass, if i buy them...

**GottaHaveLS1** · 06-10-2007, 11:17 AM

I have a feeling the 02 sims will get rid of the codes thrown by the rear 02's. There is no sniffer test in CT, but i'm wondering if it would be ok to drive around with open bungs in the exhaust pipes. The 02 sims wont fill the bungs after the cats on a stock y pipe, right?

**SSpdDmon** · 06-11-2007, 05:34 AM

Originally Posted by GottaHaveLS1

I have a feeling the 02 sims will get rid of the codes thrown by the rear 02's. There is no sniffer test in CT, but i'm wondering if it would be ok to drive around with open bungs in the exhaust pipes. The 02 sims wont fill the bungs after the cats on a stock y pipe, right?

You don't want an open bung, no. If you're dead set on getting sims, you can do that to eliminate the rear O2 codes. They will plug into the same connection the O2's plug into now. Once connected, I would zip tie them up and out of the way of any heat sources (e.g. trans). Then, you could leave the failing O2's in the bungs to act like plugs and zip tie them (now unconnected) up and out of the way too.

If you run without anything filling the bung holes (

- sorry, that just sounded funny), you will have a nasty ticking sound that'll raise eyebrows AND you most likely will have fueling troubles. Any fresh air that get's into the exhaust stream near the front O2's can appear as a 'lean' mixture in the eyes of the PCM. In turn, the PCM will try to compensate by adding more fuel via the fuel trims until it no longer sees that lean mixture. That's why I tell everyone who asks not to run open headers. It'll flood the engine after a few minutes of closed loop operation (closed loop kicks in once coolant temps break 100*F).

**GottaHaveLS1** · 06-14-2007, 11:56 AM

Originally Posted by SSpdDmon

You don't want an open bung, no. If you're dead set on getting sims, you can do that to eliminate the rear O2 codes. They will plug into the same connection the O2's plug into now. Once connected, I would zip tie them up and out of the way of any heat sources (e.g. trans). Then, you could leave the failing O2's in the bungs to act like plugs and zip tie them (now unconnected) up and out of the way too.

If you run without anything filling the bung holes (

- sorry, that just sounded funny), you will have a nasty ticking sound that'll raise eyebrows AND you most likely will have fueling troubles. Any fresh air that get's into the exhaust stream near the front O2's can appear as a 'lean' mixture in the eyes of the PCM. In turn, the PCM will try to compensate by adding more fuel via the fuel trims until it no longer sees that lean mixture. That's why I tell everyone who asks not to run open headers. It'll flood the engine after a few minutes of closed loop operation (closed loop kicks in once coolant temps break 100*F).

Alright, i'll do that. Thanks for the help.