fiskarflugen

The PO of my 91 964 put in a brand name performance chip and I have problems with the car stalling at speed on rainy days. Am trying several fixes, ie cleaning AFM connection, new O2 sensor, etc. I would like to go back to a "stock chip". Stupid question --what is the best place to get a stock chip? Is it safe to buy a used one?

joey bagadonuts

A forum request for such a part is usually fruitful (here and elsewhere). Just make sure you get the correct chip for the ECU in your car.



Your ECU part number is noted on its cover below "Bosch". The chip will have a blank label with just the part # (126735 ...):

fiskarflugen

So in your example I would be seeking Chip #1267356142 or do I ask for the Eprom and cksum#'s corresponding to the ECU#? Thanks a bunch Joey

mada1

That is very interesting. How does that play out when you put in an aftermarket chip?

joey bagadonuts

Exactly. That's the chip that goes with the ECU example. You're welcome.
When I bought my EVO Motorsport GIAC chip, they asked for model year. I guess they had various models. I'm not sure if Steve Wong programs his chips for a specific model year or ECU or offers chips that will work for all ECU's used with the 964's. But it's a good question to ask.

fiskarflugen

The PO put in an Autothority chip, cat bypass and K&N filter. I have a problem at the track the other day where when the car got hot that the "check engine light" came on. Would go off after car was shutoff and cooled down, but came on again when it got hot. On the drive home, the light did not come on, but the car just sputtered and died while going about 50 mph. It was raining too. I did a search here and among the many possibilities, a "bad chip" has been sighted. This may not be the fix, but I wonder with the other modifications.....can I go back t stock or do I now need a Wong chip given the other changes made to the car???

ValveFloat

I had the same thing with an Autothority chip. The bonus was I couldn't read the codes out because the Autothority programing was based on early 964 stuff, before the built in code reader stuff was there.
I now have a SW chip, no CE light, and the code read works.

fiskarflugen

Yup- i tried reading the codes this weekend too and the chip disabled that. Good to know the SW chip fixed that. I guess I was hoping to be able to put in the stock ship to save some dough. Thanks for the post.