I replaced the original Bosch LH-SFI EPROM (2 287 358 443)chip with the PAD Performance Chip.

Easy to do: Locate BASE MODULE and remove fuse #2 (provides power for LH-SFI module); then remove LH-SFI module; remove four (4) screws from front and four (4) screws from rear. Then remove six (6) screws holding the pc board. Then remove pc board assembly. Fold board down and replace original EPROM with the PAD chip. If you need more directions and where's it's located, check my page under menu #6.

Do the reverse to put back together!

After installing into car, I went for a test drive. The acceleration is very nice at low rpm, much improved over stock chip. The 1500-2000prm performance is greatly improved, lots of power! From 2500 3500rpm, the car, which always had good performance, is very special. From 75mph to 95mph in a wink. Also has K&N filters.

The car also idles very smoothly. All in all, a good chip.

Then I decided to see what the Lambda tester thought of this new chip. I wish I hadn't although it's probably good that I did! At idle, the lambda is about 70% oscillating from 65% to 85%. That's RICH!
With the stock chip, the lambda at idle is 45% to 55%.

At 2500rpm, the lambda was around 55% to 65%. As soon it was returned back to idle, the lambda shoots up to 75% as before. With the stock chip, it's oscillates around 40% to 50%.

That stands to reason doesn't it? In order to get that kind of power, the injection duration has to be changed to 'stick' a little bit more fuel into the cylinder. Thus it runs richer than stock.

But so much so, that I fear for my cat converter. At a lambda of "1", the air/fuel mixture generates products (HC, COx, NOx) that the cat converter was designed to handle. With the PAD chip, the cat is definitely working harder! Am I correct about this?

Anyway, since I'm not interested in that kind of performance (anyone seen the price of gas in California lately?), my PAD chip is up for sale, $125! Works in any '92 to '95 MB V8 engine. First come, first serve! Please send me E-MAIL; do not reply here. TIA.

EDITED by JimF: 5/11/01:
Per "stevebfl", the correct interpretation is NOT rich but LEAN when reading the Lambda tester. So cat is ok!

[Edited by JimF on 05-11-2001 at 01:02 PM]

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

After looking at the O2 sensor/Lambda curve, I may have been overly critical with the cat analysis.

Check out the picture below. http://pages.prodigy.net/jforgione/AirFuel.jpg
The picture shows the closed loop performance of a MB's O2 sensor "lock range".

Even at 80%, the Lambda value ranges from 0.997 to 1.03. This kind of range is what you see in these 'performance' chips. And this should not overstress the cat.

Would appreciate comments?

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

At the rising $$$ for petro, stay stock.
That's what's nice about havin' da "CUBES" of the
V/8.
Still have plenty of grunt without the bad [RICH]
MPG's.

Received the installation instructions today and it says;

"The Power+Chip is intended for off-road use only. It is not approved for use on automobiles in states with pollution control laws. However, your vehicle will pass smog inspections with the chip installed if it is kept tuned to factory specifications."

So guess I was wrong but, the astute person might ask ". . how do you keep it tuned to FACTORY specifications when a chip that ALTERS factory specs is used"? It is that very chip that sets injector duration and timing, so what gives?

Just playing devils advocate here! Any comments?

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

What you need Jim, is two chips with an A/B switch.
Now there is an idea.

You mean like a Prompaq?

See: http://cgi.ebay.com/ebaymotors/aw-cgi/ebayISAPI.dll?ViewItem&item=585215488&r=0&t=0

Willy

__________________
Willy

'94 E420 White

Mods
-------
Berg Werks Keyless Entry
Buzzer replaced with Chime
Dash Light Upgrade
Burlwood/Leather shift knob
Alpine CDA-9815 Head Unit
2002/2003 16" C Class 7-Spoke Wheels
Updated "Chip" to fix Code 19 problem

Arthur, ask and you shall receive!

Willy, wow, that's some contraption! Wonder how much it cost originally? From the looks of it, it could be adapted for use on an MB without much difficulty.

Probably runs on 12V battery and the ribbon cable plugs into the vacated socket in the LH ECU. Just what every MB S500 owner needs.

Anyway, I think I pass on bidding.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Not sure what they originally cost and can't yet find a web site for them. All I know so far is that the PromPaq can be bought from Adaptive Technologies in Port Hueneme, CA. (800) 677-6672 or (805) 488-8832 (in CA).

Come to think of it, things can double as a kill switch.

Willy

__________________
Willy

'94 E420 White

Mods
-------
Berg Werks Keyless Entry
Buzzer replaced with Chime
Dash Light Upgrade
Burlwood/Leather shift knob
Alpine CDA-9815 Head Unit
2002/2003 16" C Class 7-Spoke Wheels
Updated "Chip" to fix Code 19 problem

Guess all you need now is a designated
label.

How about Power Mode Control ?? Nope, Wait a minute..... "Power Mood Control"
Yeah, That's it-- PMC !! I like it !!