It changes per the ROW vs USA and CAT and non CAT exhaust..........what do you have on the race car?

 

The coding plug in the car is part # 928-607-438-00 I think it is a standard ROW manual coding plug...not the USA catalytic coding plug? I wonder if that changes things?

 

If you lookon PET "V pages" you will see that it is for manual transmission with cats.

 

What do the spark plugs look like? How is the idle?

 

Looks pretty good, especially since you are getting max hp at 6100 and not 5100

the fuel curve looks funny and makes me think it was measured with the tail pipe sensor. was it? interesting that you get that rich at the end with a stock fuel regulator.

the coding plug is a dead end plug with selectable connections. I set mine to the catless setting.

 

Its selectable. I dont have the drawing handy, but i can find it if you cant. I think its in the manual.
mk

 

Okay so I have the stock coding plug....... might as well change it to the non CAT ROW coding plug since its only $20....

So what difference does the USA-cat coding plug change in the LH-EZK that the ROW non cat does....would the non cat run leaner since it doesn't need as much fuel to heat the cats?? Or would in be the opposite?

yes the measurement was taken from the tailpipe....

I haven't seen the plugs yet, but the idle is fine

 

you can change the coding plug manually, by taking it apart and following the configuration listed in the WSM.

the tailpipe measurement is worthless, especially at the early rpms in a dyno run. get the wide band that screws into the 02 sensor hole and just disconnect the O2 sensor at the fuse panel. we did a back to back run to see if the o2 sensor changed anything, and it didnt. hp was within .25HP with and without the o2 sensor connected. quite possibly you are just fine with the stock regulator. before you do anything, look at the plugs after many full throttle runs and see what they look like. after cruise, they all look clean during mainly in the closed loop operation.

mk

 

MK
This sounds like a plan.....my "seat of the pants" impressions are not that there is anything wrong with the engine....it runs just fine....

Until I get a firm answer on exactly what effects the coding plug will have, I'll just leave it for now....

WB02 is on the list!! The bummer is it only reads from one bank....

 

928 607 438 00 is the coding plug for the '89 S4 5 speed w/cats...........as Mark indicates its an easy fix for your set up; see the 89 S4 spec book.

 

put it this way, headers, exhaust, coding plug brought the RWHP from 292 to 335rwhp. I dont know what was responsible for what, but I did get a 40hp gain . I also dont know what the GT like cam is worth, but dont think its worth all of the gains.

mk

 

Next time I'm at shop I will change the coding plug to the ROW setup.....then have the car dyno'd again....we'll see...maybe monday?

 

If you just plug in a non cat coding plug you also need to fit a idle mixture pot and a shorting link where the (disconnected) O2 sensor plugs into the harness. I do nopt recommend this !!

You are fine with the stock cat coding plug that you have. The headers can mess up the top end mixture. You need to remap it, not bodge it.

 

So thats the answer I was looking for........ I'll install a fuel pressure gauge on the rail just too see where things are at for the next test.....

 

Nick Skudder (DRNick) found as soon as he fitted a set of headers to his orange monster that it ran much too rich at the top end....