Catless and the imfamous CEL

[5.0_Lojos]

Can someone give be the best solution now that I am "Catless" Upon driving the car it did feel different. It's not my daily driver and my commute was short. I did step on it a bit and felt responsive but on the lower rpm I had some sort of surge or stutter if this makes sense.

Waiting on my tuner to get back to me but he did indicate a tune revision is not necessary when modifying or going catless...

@engineermike
@K4fxd
You guys seem to be Tuners at some capacity... My next drive is this coming Thursday back to the shop to add the 18" bottle style vibrant resonators.

Sponsored

 

[tosha]

Subscribed to the thread. @5.0_Lojos , can you please record the sound and share some underbody pictures after resonators install? I am contemplating doing the same.

@engineermike , what options are possible? Would it be possible to turn off rear o2 with pcmtec or some other solution for somebody who never done tuning before? I have roush stage 2 supercharger with whateve roush tune came with it. Would appreciate any insights.

 

[5.0_Lojos]

Subscribed to the thread. @5.0_Lojos , can you please record the sound and share some underbody pictures after resonators install? I am contemplating doing the same.

@engineermike , what options are possible? Would it be possible to turn off rear o2 with pcmtec or some other solution for somebody who never done tuning before? I have roush stage 2 supercharger with whateve roush tune came with it. Would appreciate any insights.

Will do. My only premise for cat removal was to prevent or have a peace of mind of not melting one in the process being that I am procharged. As I heard before, It may or may not ever happen. And, don't mind the extra power and less exhaust restrictions. If I were N/A probably not worth it...

 

[ice445]

Will do. My only premise for cat removal was to prevent or have a peace of mind of not melting one in the process being that I am procharged. As I heard before, It may or may not ever happen. And, don't mind the extra power and less exhaust restrictions. If I were N/A probably not worth it...

Yeah, boosted you're kinda damned if you do, damned if you don't when it comes to cat deletion. The best solution is probably adapting gt500 cats or using the highest quality aftermarket ones, but that adds big $$ to an already expensive install.

 

[engineermike]

@tosha the “right” way to delete cats (if it were legal) while minimizing other issues would be to turn off FAOSC and use the anti-foulers. Pcmtec gives you access to 10,000 parameters but that’s not one of them. Most big tuners won’t do it either because they value their business and fear jail time.

 

[K4fxd]

It's criminal what the EPA has done to the auto aftermarket. It is the only agency that holds companies responsible for what end users do with a product.

If other product laws and regs were the same, Jack Daniels and GM would be liable for John Smith getting drunk on old number 7, driving a camaro and crashing into your house.

We have an election coming up, lets vote for people who will reign in this lawless agency.

 

[5.0_Lojos]

@tosha the “right” way to delete cats (if it were legal) while minimizing other issues would be to turn off FAOSC and use the anti-foulers. Pcmtec gives you access to 10,000 parameters but that’s not one of them. Most big tuners won’t do it either because they value their business and fear jail time.

Prob dumb question but how would the epa know if a tuner turned it off? Or does the software not have the feature in place to do so? Understand everything is trackable but just curious...

 

[K4fxd]

rob dumb question but how would the epa know if a tuner turned it off? Or does the software not have the feature in place to do so? Understand everything is trackable but just curious...

If the software allows the turning off of such things the EPA gets it's panties in a wad.

PcmTec does not allow a tuner to turn it off. Nor do current versions of other tuning software.

 

[tosha]

@tosha the “right” way to delete cats (if it were legal) while minimizing other issues would be to turn off FAOSC and use the anti-foulers. Pcmtec gives you access to 10,000 parameters but that’s not one of them. Most big tuners won’t do it either because they value their business and fear jail time.

Understood that reputable tuners won't touch it. but considering I'm not even in US and I'm looking to create a swappable setup that would allow me to run catless on tracks and put back cats for street use in between the seasons, what could be the options?

Or am I overthinking this and track use would be fine with no cats and roush tune as is?


Any opinion and level of detail would be very much appreciated

 

[K4fxd]

Understood that reputable tuners won't touch it. but considering I'm not even in US and I'm looking to create a swappable setup that would allow me to run catless on tracks and put back cats for street use in between the seasons, what could be the options?

I "think" the world package of PCMtec still has the option of turning off rear sensors and FAOSC.

Unfortunately the EPA has told manufacturers if you want to do business in the US you must comply with our wishes.

If you tune yourself PM me.

 

[5.0_Lojos]

@K4fxd would a 90 deg mini cat defouler work just fine? And, as far as performance, I read that you mentioned that no issues should be noted in terms of O2 signaling on AFR?

 

[K4fxd]

would a 90 deg mini cat defouler work just fine? And, as far as performance, I read that you mentioned that no issues should be noted in terms of O2 signaling on AFR?

The defouler will, or might keep the check engine light off. It will do nothing for the car.

As stated by Mike, myself and others the ECU uses the rear O2 sensors in the logic for A/F ratio. No cats and the rear O2's and FAOSC logic on the A/F ratio or lambda will not be what you are logging. It will vary as the widebands age.

The million dollar question is how much will it be off. I will assume each car will be different. I think the Roush tune is safe enough it shouldn't be a problem. But one doesn't know till one tries it. That said there are hundreds of Roush tuned FI cars without cats doing just fine.

 

[ZXMustang]

Ford's logic uses the rear narrow band O2 sensors to fine tune the front widebands. That is what FAOSC does.

If FAOSC is on the rears get a bogus reading and constantly try to get the fronts in range, so to speak. This will cause the ECU to misread the actual lambda.

How far out will it be? IDK, It will be off

If you turn off FAOSC things should be OK due to the widebands using outside air for calibration.

How often do they calibrate? IDK.

If the widebands calibrate everytime you start the car I can't see it being much of an issue even with FAOSC on., unless you are running on the ragged edge. Lots of catless race cars are doing just fine, so I don't think it is a big issue but something to be aware of.

Yeah I have that disabled in my tune. Along with all the 0420/0430 codes. Also have COT disabled as well.

 

[junits15]

@K4fxd is right on and I would add that I did test the effects of cats on FAOSC and the difference was 10-15%. So if the cats are gone and FAOSC is still active then your a/f ratio could be off by as much as 1.8 and you’d never know it because your factory widebands are lying to you. I’d also add that many tuning softwares and tuners won’t disable the FAOSC anymore. I’m not so much worried about losing the calibration as I am incorrect calibration.

This interests me greatly, because if I'm understanding you right this is a real 10-15% error not just 10-15% fuel trim. That concerns me, as if I'm not mistaken, that will make us 10-15% lean. The thing I'm not understanding is if this is true, I would think there would be a clear link between cars using headers with non-foulers and a higher than average failure rate.

I know you've mentioned this a while ago and I thought about it a lot then too, the thing I couldn't get over was that if this is the case, this could be a risky situation for stock cars with damaged cats. The biasing scheme would be wrong then.

Do you mind sharing a bit of info on how you tested this? Did you use an external wideband sensor? I'm curious to learn more, I'm running with aftermarket cats with FAOSC on, I have heard that if I disable FAOSC my cat monitor will go not-ready. That will make me fail emissions, so believe I need to leave this on. PCMT wont let me edit it any more anyway.

 

[WildHorse]

Or am I overthinking this

100% correct. I have 2 tunes. FAOSC on (CEL on), FAOSC off (by another independent tuner NOT connected with any company). Neither was detrimental. Stinks more with FAOSC on.

Sponsored