[rich123321]

Hey guys. Thinking about getting a permanent cat simulator. I may not be running a tune 24/7 as I will be back and forth between school. Is it safe for long term fuel trims to use a cat simulator so I don't have an engine light when my time isnt installed?

[hardparker]

It will skew the fuel trims if left in. Only put it in to pass inspection if you're catless and hope they don't do a visual.

[obriennathaniel]

Originally Posted by hardparker

It will skew the fuel trims if left in. Only put it in to pass inspection if you're catless and hope they don't do a visual.

Ditto.

[rich123321]

Originally Posted by hardparker

It will skew the fuel trims if left in. Only put it in to pass inspection if you're catless and hope they don't do a visual.

What about a mini cat instead of a simulator?

[mike@x-ph.com]

I would not keep these products installed all the time

[Tiago@VRSF]

The N55 doesn't use the rear o2 signal for fuel corrections like the N54. There won't be any harm in leaving it on long term but if you're concerned they can be easily removed at any time.

[Tchao]

Correct. The DME does not use the lowband o2 for fuel trims. Thats the job of the wideband o2 upstream.
The lowband is only used to measure cat efficiency.

I have mine on 24/7 for about 10k now. Datalogging with JB4 and zero issues with fueling.

[rich123321]

Originally Posted by Tchao

Correct. The DME does not use the lowband o2 for fuel trims. Thats the job of the wideband o2 upstream.
The lowband is only used to measure cat efficiency.

I have mine on 24/7 for about 10k now. Datalogging with JB4 and zero issues with fueling.

What sim are you using, and how is the installation?

[Tchao]

Im using the CatSim from Canada, I believe its the same sim most of the members here use.

I installed a few inches from the plug terminal of the O2 harness with the engine harness on the valvecover. The module itself is placed though the weather seal next to my JB4 unit.

Hope this helps.

[Jadar]

Originally Posted by rich123321

What sim are you using, and how is the installation?

Their instructions are pretty vague but it can be figured out search online there's some better wiring instructions.
A lot of us on here run it very successfully. You can even get a plug and play kit.

"For Rent and For Sale"-io2 V3.1 Sim" http://f30.bimmerpost.com/forums/sho....php?t=1384030

http://f30.bimmerpost.com/forums/sho....php?t=1367209

[Chicken_Joe]

Originally Posted by Tiago@VRSF

The N55 doesn't use the rear o2 signal for fuel corrections like the N54. There won't be any harm in leaving it on long term but if you're concerned they can be easily removed at any time.

It actually will as I left mine in for about 3 months and my car slowed down noticeably. The device starts to pull timing from the engine.

[Tchao]

Originally Posted by Chicken_Joe

It actually will as I left mine in for about 3 months and my car slowed down noticeably. The device starts to pull timing from the engine.

Please show me how you know that?
What three months did you leave it on?

Im near 10-11k now (almost 3 oil changes ago) and zero fueling changes.

[Chicken_Joe]

Originally Posted by Tchao

Please show me how you know that?
What three months did you leave it on?

Im near 10-11k now (almost 3 oil changes ago) and zero fueling changes.

I never had dueling issues I had timing issues. My car was slowing down during winter bro. Like it was slow. Felt like nap 1 when I would run map 5 and I have full exhaust, downpipe and ff wires

[Tchao]

Hmm I'm on stock flash still, so my timing is more erratic, but JB4 never recorded anything that wasnt there before the CatSim. Ive been using E30% since last fall and it looks pretty much the same. Granted my IATs are north of 130F now since its summer here in AZ, so some timing loss. It averages 2.2 degrees all winter long on map2 pre- and post Sim.

Not trying to argue, but if you are right, this means some of the DME guys are wrong about the lowband signals, it probably wont be good to keep it on.

Eitherway, I need to get a flash tune, and throw JB4 and CatSim away.

[Chicken_Joe]

Dejan and I have conversed about this subject a few times. I don't leave mine on

[Jadar]

Originally Posted by Tchao

Hmm I'm on stock flash still, so my timing is more erratic, but JB4 never recorded anything that wasnt there before the CatSim. Ive been using E30% since last fall and it looks pretty much the same. Granted my IATs are north of 130F now since its summer here in AZ, so some timing loss. It averages 2.2 degrees all winter long on map2 pre- and post Sim.

Not trying to argue, but if you are right, this means some of the DME guys are wrong about the lowband signals, it probably wont be good to keep it on.

Eitherway, I need to get a flash tune, and throw JB4 and CatSim away.

I wouldn't throw away the cat sim, you'll need it to pass emissions. There is a plug n play solution.

As for tossing the jb4 instead of a flash makes sense if you're on a stock turbo. On PWG cars with bigger turbos you'll need that jb4 for boost control. I don't care what anyone says I've ran two different flash tunes on my PS1 and the DME tapers the boost. Anything I've tried with adjustments only led to higher spikes down low and killing the fueling HPFP up top. Jb4 will be needed and to date a BEF and a jb4 stack is the best and most proven route for upgraded turbos.

EWG cars are different and can get away with flash only and produce much better and more consistent results but the boost still tapers. Just something to think about if you plan on bigger turbos down the road.

[Tchao]

Originally Posted by Dejan_

I wouldn't throw away the cat sim, you'll need it to pass emissions.

Correct me if Im wrong but doesnt a flash get rid of the rear o2, making you 7/8 ready, which for most states will pass? If not, then this sucks.

[Jadar]

Originally Posted by Tchao

Correct me if Im wrong but doesnt a flash get rid of the rear o2, making you 7/8 ready, which for most states will pass? If not, then this sucks.

A flash will not put it into readiness. It will be incomplete. I had to flash back to stock and run the cat sim. The only thing the flash will do is keep the CEL off.