Thermal couplers + Test pipes

Excellent summary and good move on your part.

 

Essentially what I said in post 40.

Dave, not only did cars not have EGT systems before cats (at least the cars I know) but may cars with cats don't have them.

 

You could add the bungs for the Tc in your test pipes if you want. I assume the test pipes have 02 sensor bungs ?

One of the things that I have been working on understanding is the relationship between the Tc output and CEL. There is a relationship in that there are obd codes that reference cat temps. So, In that case I believe you would have to do the jev fix in order to fake out the ecu on the temps.

Your summary is prudent and is what I was advocating from the beginning. Regardless of where the Tc is located and where the overheating situation is coming from it is a good safety feature as evidenced by Ketel's experience.

 

The egt's wouldn't get hot enough without cats to trip an sdl, so the system doesn't really serve a purpose without them.

In Kettel's case, it was either the cat itself causing the restriction or trapping and burning up excessive unburned fuel in that bank, neither of which happen without a cat in place,so no the cat temp ecu wouldn't have done anything for him if he had test pipes. If the case was too much fuel, the car would have fouled a plug before too long anyway. If it was the cat,well then without cats there is no problem for the system to catch.

 

This discussion jogged my memory banks a bit, so if you were to run test pipes and wanted to monitor your egt's, I would use this system. The stock system would never trigger as the trigger is not until over 1700 deg F and the engine would melt down before the EGT's ever got that high that far down stream without a cat converter igniting the unburnt gas.

Automotive :: Ferrari Catalytic Converter Instrument and ECU Controller - Aerospace Logic Inc.

Anyway, if I were to want a functioning egt monitoring system for my test pipe equipped car, that's what I'd use as the factory system would be useless in that case.

 

Man these threads confuse the hell out of me.......which does not take much when it comes to stuff like this by the way. So on a 5.2 car, can you run test pipes safely with a TUBI and not get a cel???

 

Marcus, The SDL is a function of a warning system that monitors exhaust gas temperature and does so inside the CAT's.

The CEL's that come from running test pipes are based on the post CAT O2 sensors since they are doing their job by telling the system "Hey, the CAT's are not working".

 

Got ya, so would you advise against running test pipes? No inspections here by the way.

 

I probably wouldn't, even on a 2.7 car. Only reason I have test pipes is that's how it came and I'm contemplating putting the cats back on, tbh.

 

I was considering test pipes and I fully vetted the option.

I decided against it for the following reasons:

1) I don't want to smell the stink
2) I don't want to risk and issues with the car based on the result of messing with the O2 sensor functions.

At some point, I plan to get hi-flow CAT's.

 

spacers for the rear o2 sensors with test pipes on should technically fool the engine ecu, that all is normal.. but ive read even with the spacers its still not 100% full proof..meaning a CEL can still pop every now and then.. but less often..

Fabspeed sells them. $150 for a pair.

now in terms of disabling the TC control boxes with test pipes on.. thats a whole other came. initially i thought it wouldnt throw any CEL codes.. but it will.. as the engine ECU is no longer getting a signal from the TC boxes..

a few posts back.. a guys outlined 4 different setups.. ON, OFF, connected, disconnected.. etc.etc..

and in all cases it threw a cocktail of CEL and SDL codes.. depending on the variation..

so ive already thrown in the towel on this subject.. Im no electrician like that guy Jevs, so im just going to accept the system how its supposed to operate and thats it. if the TC boxes break, buy new ones, which mine have and will buy etc..

run the car, enjoy the car, keep an eye on things regualarly, keep an eye on temps gauges in car.. and if anything happens with the SDL, i'll do as it says, to slow down or pull over if solid. and thats it lol..

ive owned my car 2 weeks and it already rules me, and it will continue to, so why fight with it..

will put in a Nouvalari Supersport exhaust and call it a day..

 

I know you many of you guys are young and the idea of a few more HP sounds great but on the street what you get from test pipes over high flow cats is less than insignificant. I would not waste a dime on test pipes, particularly given the other problems they may generate. FYI, a good read about cats, OEM vs high flow vs test pipes. If you really want to waste a grand on a couple of feet of SS tubing be my guest. A new set set of plugs will probably get you more.

Catalytic Converters - Stock vs. Aftermarket Cats - Import Tuner Magazine

 

John,

My motivation when I considered test pipes was:

1) Loudness (sure, I'll take more)
2) Reduce heat in the exhaust
3) Remove breakdown of the CATs

HP was never my goal.

But, as I said, I vetted it and plan to only do hi flow CAT's in the future.

 

for now..luckily my oem cats are literally brand new.. I have the Ricambi receipt in the history folder of my car.. just checked it $6200 for the pair.. totally ridiculous..

my stock headers are also in good shape for now.. so in terms of headers/cats I should be ok for a while..

my thoughts to go test pipes.. was to reduce overall heat and prolong life of headers..

but my car has a challenge grill.. so that should help some..

when the time comes.. i'll do as Dave, and invest in a set of high flow cats..

 

I think at this point I am also with Dave, hi-Flo cats or bust.

 

SDL and CEL are two different issues. The interrelationship between them is not clear. The TC send information to the main ECU not only to trigger the SDL system but the ECU also uses the EGT measurements and reacts to them in triggering CEL as well. Attached are the OBD codes that reference the EGT readings. I have got these codes and CELs.

If you disable the TC/EGECU system you will most likely have CEL issues as well.

The whole system is meant to function together with Cats, 02 sensors, TC and EGECUs.

This is why you need the TC system even if you decide to run test pipes.
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It seems that if you do run test pipes and then contain a place for TC's, then the EGT system can stay in place and will likely never be a problem because the temps will never reach the threshold to trigger a SDL.

You can see Fabspeed's test pipes have all bungs required for O2 sensors and TC's.

Ferrari F355 Primary Catbypass Pipes - Fabspeed Motorsport

I may be incorrect, however, I believe Bob has posted OBDII codes from a 360 and note, some many be the same as 355, but not all - use with caution.

 

Exactly which is why I said to tie the TC up out of the way with test pipes is not a good idea. As I said earlier, if you decide to get test pipes make sure they have bungs for the TC or have them added.

Those codes in my post are correct for a 355. I have confirmed this with a Ferrari tech.

 

Could be a miss print.

P144g is P1448 on a 355

PI449 is P1449 on a 355

Just letting folks know.

P1445 (bank 1), P1448 (bypass valve) and P1449 (bank 2) are all related to the 3 TC's.

 

Thats a screen shot of a pdf that was probably made from a scan of a document that didnt convert the text correctly. 144s is 1445 and 144g is 1448.

Also the prefix is P not PI. The codes a Pxxxx

I have been able to clear blinking sdl by clearing OBD codes. The SDL warning system is not a stand alone package from the OBD system. In troubleshooting and understanding how this all works I have seen the relationship between the CEL and SDL often.

 

Most certainly since there would be no other way to go into limp mode then thru the main Motronic ECU.

 

Is a steady ck engine light or a flashing ck engine light cause for more concern?

 

I'm fairly certain 335's only have a solid CEL. The SDL has 2 modes: Flashing and Solid. Flashing is a warning and Solid is limp mode.

 

Understanding the Check Engine Light

I don't think I have seen a flashing CEL, but I'm not sure. Flashing CEL according to that doc is a no go situation. The opposite of SDL.

 

Bob, without cats the exhaust will not get hot enough to trigger an sdl. The motor will melt down first, the port is too far down stream to be useful. So, it doesn't matter if you zip tie the thermo couples out of the way or put a port in for them, they won't do anything either way. They trigger a flashing light at 1720 deg f, which would be useful if they monitored the temp near the header flange, but not near the muffler inlet. If the exhaust gets that hot that far down stream, your car has already blown the motor and is on fire.