fan clutch and ecm tune questions

[niceguypmp3]

On my '03 TB, if i want to put the newer regular thermal clutch fan that's found on the newer TB's, am I able to use the factory fan shroud and fan blades? does the newer clutch fan just bolt in place? i know I would need to get the fan codes removed. which leads me to another question. Is there anything else that would be good to have Lime-Swap do to the computer other than the following:
Remove fan codes
Firm up shifts and responsiveness
Remove Torque converter slip engagement (engage torque converter at 100%)
Remove VATS (or is this not applicable to '03 model)
Throttle delay removal
Torque Management removal
increase power and mileage

 

[TollKeeper]

@limequat - Can answer most of your questions, from what I understand on the board, he listens to what you are trying to accomplish, and lets you know what he can, and cant, do.

As for the fan, its a direct swap, minus the wiring for the fan clutch. Same shroud, and fan.

I have personally been waiting to do this swap myself. But my Electro-Viscous keeps going. It was replaced by the dealer 70k miles ago..

 

[christo829]

If yours has the SAIS (Sorry, I can't remember off hand which did or did not...my 04 did), have the codes for that removed as well. That way, you can remove the pump and solenoid, then block off the solenoid port. One less potential leak and circuit to worry about.

Cheers-

Chris

 

[Mooseman]

A lot of that has been covered:

Question about having PCM tuned

 

[aaserv]

I have a similar situation with my 03. Mine is the v-8 but i think this info pertains to both. I went to gm website to check for factory software updates....and printed out 4 pages! Although at some point (after changing cam and intake, throttle body) Ill have to go to lime quat my intentions right now are to have the these factory software updates done 1st so Im on an even playing field with the later models. I went to service.gm.com and put in my VIN number and got the list of available updates with the part number for each.
This is some of the things that were updated in later model years and are available for the 03 V-8 although there may be more or less for your 6cyl.

Upgrade to throttle body control
new calibration to reduce, change settings for, or eliminate some diagnostic codes
New transmission calibration and diagnostic code settings
Updated calibration to address Fan noise and OVERHEATING conditions.
Fuel system calibration
Speedometer calibration

That covers quite a bit of problems.....What tipped me off that my fan calibrations were not right were discussions here about the Fan Clutch. Members with later models were running faster fan speeds at idle than mine is but Im getting no codes .....So for mine to be running slower but not shooting a code the computer must be telling it to run that slow.. It is and these updates will correct that. I havent had it done yet and since finding this out Ive learned that the fan speeds at least could be adjusted with HP Tuners but why not get it all done at once is my thinking. Its not necessary to have this done at a dealership also....a competent shop with paid access to GM can do it also.
Worth looking into I think...

 

[Mooseman]

That would only fix those issues only within GM's lame parameters. In other word, it would still have torque management, it won't delete the fan codes if you want to go to a thermal clutch, won't do anything for shifts, and so on. When I had a tune done for my 5.3 in the Saab, it really woke it up as well as delete the fan codes. And Jeremy can still do it probably cheaper than any shop would with a stock tune.

The reason we get the fan codes tuned out is not for correcting an issue with overheating but to be able to use a more reliable thermal clutch. Not all EV clutch failures result in a code. The codes coming up is actually quite rare. Even if the codes are deleted, you can still use an EV clutch if you wish.

 

[niceguypmp3]

If i get my ecm tuned and i drive it carefully and not be a speed demon realistically what kind of mileage improvement might I possibly see after the tune?

 

[niceguypmp3]

another question about tuning. someone prior to me cut the cat off but left the downstream oxygen sensor in place. but i don't have a check engine light coming on. if i get a tune, i would probably have the downstream oxygen sensor disregarded. in the meantime, would not having a cat but still having the downstream oxygen sensor affect anything negatively?

 

[TollKeeper]

No cat, with O2? Likely already has a tune of some sort, or a emulator some where in line with the plug..

 

[Reprise]

The downstream sensors aren't important. Even if they go out, it won't damage the cat if you don't get them replaced right away (or at all), unlike the upstream sensors. They'll just throw a code (and they're looking at minimum O2 levels, post-cat; yours probably exceeds that by a good bit, since you have no cats, which is why you don't have codes as of now.)

I'd definitely tune out the downstream sensors, if you're getting a tune done. Mine will be programmed out on the Sierra, soon.
And as Moose mentioned, definitely hit up Jeremy / Limequat for the tune; he discounts 360s (V8 or I6), and you can't get it done cheaper, as a result. Quick service, too.

 

[Mooseman]

If i get my ecm tuned and i drive it carefully and not be a speed demon realistically what kind of mileage improvement might I possibly see after the tune?

Not much for mileage. Mostly driveability improvements.

another question about tuning. someone prior to me cut the cat off but left the downstream oxygen sensor in place. but i don't have a check engine light coming on. if i get a tune, i would probably have the downstream oxygen sensor disregarded. in the meantime, would not having a cat but still having the downstream oxygen sensor affect anything negatively?

Either it's been tuned already or he added a spark plug defouler spacer to the downstream O2 sensor.

 

[niceguypmp3]

i know on some vehicles you need the backpressure of an installed cat in order to run properly. what about these TB's? since my cat has been removed, what effect will that have on the power and mileage? When i get it tuned by limeswap then does he tune it specifically for not having a cat if it's been removed?

 

[Mooseman]

I would imagine he could tune it with no cat however, the stock exhaust system has very little backpressure therefore I don't think this engine relies on it. Talk with @limequat about it.

 

[limequat]

Agreed, the less backpressure the better.
Conversely, the cat isn't the restriction in the system, so probably not much impact from removing it. The only thing I do for a cat delete is to remove the codes.