Damian in NJ

Chris, he has the new chip ready, I'm sending back the 'bad' one tomorrow.

flash968

i should receive the new promax chips any time now and will test them to see if the curve changed - it is likely that if the light is as a result of mixture issues with US spec cars, as they have theorized, then the outputs may be reduced

as for the CEL being on some and not others, it is not reasonable that it would affect some US cars and not others, on the presumption that the diagnostic systems work properly and all other items are functioning properly, and it is the same DME - the question of which DME and chip combination works has been an issue, and to date only one combination has been established by promax as working with their chip - so far, their contention is that the CEL is specific to US cars - they say they have fixed it - i will see shortly, and will let everyone know what i find

fingers crossed

Luis de Prat

RoW cars have no "check engine light," so no problem there.

Today we fitted two cars here in Barcelona with the ProMax 968 chip - a Euro spec 968 and a U.S. spec 968 that belongs to Rennlister Pitou. Sure enough, the CEL appeared in the U.S. car.

However, I had the chance to experience the transformation in both cars first hand, and it was truly noticeable. We did some timed runs, too, and in our inexperienced hands both cars did 0-100 km/h in right under 6.8 seconds, and 50-100 km/h in 5.5 seconds.

Pitou is getting fault code 1141 which I hope to look up in the 944S2 FSMs (fault codes should be the same, no?) and is looking to get a corrected ProMax chip to eliminate the CEL issue.

As for me, I'm slowly gathering the courage to chip my stock 951 cab...

Damian in NJ

I should have my 'new' Promax chip in the post tomorrow, so I'll have it fitted sometime this week. I'm doubly awaiting the results, as Andrew of Promax says best results occur with a high flow cat and tuned exhaust, which I have. When I drove the car with the Promax chip in it felt great, but I didn't really push it. With the new BK underbrace and some suspension tuning I've done since I think this will really work well, all in the safe rev zone.

flash968

the fault code 1141 is "faulty control unit", referring to the DME - it doesn't like the chip

Luis de Prat

I figured as much. This is in line with stringent U.S. emissions regulations forcing Porsche to fit a more conservative stock chip in the 968.

Note that both of these cars (92 RoW and 92 U.S.A.) had the same DME and identical stock chips.

Macca

Hi Luis,

If both cars have the same chip and DME then why does one throw a CEL light? Are you saying that the ROW car doesnt have the light physically in the dash at all?

Also Andrew at Promax claims the 7100 rpm chip for the ROW cars is likely to make a little more power than the US chip - why would ROW cars make more power if DME etc was the same (assume same RON fuel)?

Just a few questions. I have an ex Japan RHD 968 (assume ROW?) and have just ordered Andrews ROW 7100 rpm chip for my car...interested in your thoughts

Cheers

flash968

which dme was in the car is actually dependent on what month in 91 the car was built - from july to sept it was the first one, with a chip specific only to that one - then from sept 91 to dec 91 it was the second with the second chip - this is the one upon which promax developed their first chip - then from then on it was the second dme with the third chip - this is the one that the racer x chip is based on - this is also the one promax used for the second go around (i sent it to them myself) - don't know why it still trips the light in a later dme like on pitou's car

these dmes are not "interchangeable", and the chips that work in the second one don't work in the first, and visa versa - weltmeister found this out the hard way many years ago, and took quite a bruising for it - both they and autothority now make chips specific to each dme setup - so far, they are the only companies to do this in the states (don't know about overseas)

Luis de Prat

Exactly.

Japan should be the same is RoW, but each individual market had specific differences, so the car could be equipped with the "check engine" diagnostic feature.

As for possible causes of Pitou's car having the CEL issue upon fitting the chip, I will add that this was the ProMAX 7700 rpm chip, not the lower RPM iteration.

Again, both cars had identical DMEs and stock chips (numbers matched), so there should be no difference aside from the "check engine" diagnostic feature present in the U.S. spec car.

flash968

which is exactly why it should have worked - he had the later dme and the 7700 promax was developed on a chip for that dme, and not the earlier one - it looks like there is still something going wrong with that chip to continue to throw the light - i need to see the chip installed in some other cars though before making that judgement - could have been a fluke - we have a test we are trying to schedule now that will involve all 3 of their chips in both dmes

i'd like to see what things are different in the rest of the setup of the RoW - if so, does the car have a light at all? does it come on and go off right after the engine starts? (like in the US)

Macca

Flash,

I agree. I have yet to see my 968 as its new to me and with my mechanic undergoing major service. I have looked at the PET and it indicates all spedo clusters are the same except for speed markings/calibration.

What I have learnt is that the Japanese ares (mine is RHD ex Japan) are different from all others by having a secondart air temperature sensor at the muffler end of the catalytic converter set up. That means it has bot an O2 sensor and down stream from that a air temp sensor. Correspondingly there is also a fuse to control this. No other variants have this set up.

My car is 1992 6spd. I belive it is ROW. Japan were early to get lead free fuel but they have high grade fuel (100 RON being their top grade). I have bought the ROW 7100Rpm chip so it would be interesting to see if this throws the light. I believe the car is pre OBD2 and thus may have a basic CEL light configuration.

I will know within a few weeks and report back.

My guess is that the US cars may have a similar exhaust gas measuring device as the Japanese version? Maybe this is thowing the check engine light? If its not this and the ECU is the same then what could it be (fuel?)?

Cheers

Luis de Prat

Both cars are MY 1992 -how is this the "later DME"? IIRC, the first 968 MY was 1992.

As for the light, no it is not present in the RoW cars. At least the ones in Europe.

flash968

there are 2 dmes for 92s, as i stated above - please read about the build dates - 92s were made in 91 - depending on the month it could have later or earlier - in this case, both cars had the later one and not the early one

Luis de Prat

Both cars have an "N" in their VIN number indicating the build date was 1992, not 1991. I own a 951 car with an "M" in the VIN which was effectively built in 1991.

flash968

nope - that is the model year not the build date - the build date can be found on the inside of the door - i also verified the date with pitou - his was built in 11/91 - that verifies, along with the part number from his ecu, that he had the later ecu - he also had the second of the three chips