colmfmurphy

@lowpue email sent to Dundon. I’ll post up when I hear back...

Thanks!!

NuttyProfessor

I'm not an engine builder and so maybe someone here that has taken Jake Raby's engine class can chime in, but while it may seem they're very close in design, inside on these engines is another story. For example, Porsche increased the displacement to 3.8L for the Carreras. That meant a larger bore and stroke which translated to higher HP numbers. While the two engines used similar "VarioCam+" systems, timing on the newer M97 was modified to support the increased HP and torque requirements. Seems to me the engine management software was working overtime to keep this engine running. I'm surprised you didn't get more codes.

z driver 88t

Another option would be to run a custom tune. Put the car on a dyno and tune to the correct AFR. Even lean it out a little to get you through smog. I came from the world of custom tuned ECUs for Japanese cars years ago. I'm honestly not sure what's available in the Porsche world, but if this is an option it would be a heck of a lot easier than pulling the engine again.

Imo000

If CA is also scanning the ECU during the emission test then it needs to have a working OBD2 port with the Check engine light off and the drive cycle complete or else it will fail. That's how it was up here until last April when then finally got rid of the emission testing.

yelcab

California does not require tail pipe testing for 2000 or later models anymore. All they do is plug in an OBD2 scanner and if everything is good, you pass.

colmfmurphy

@NuttyProfessor my 07 motor is a 3.6l and is pretty identical to the 02 at least on the outside. Ancillary parts are all identical. I don’t believe the 997.1 motor is all that different mechanically to the 02 996 motor. A ton of the parts on the 997 have 996 part numbers...

colmfmurphy

@z driver 88t @Imo000 @yelcab Yes, CA is simply a plug in now, no sniffing... they do a visual of the engine bay to make sure nothing looks amiss, check the dash to make sure the CEL is not on and that’s pretty much it. Pass or don’t pass... While in this particular case it’s a pain, I do think our relatively clean air is worth having ...

yelcab

They are supposed to check your timing, the presence of a correct cat converter and any exhaust modification. Anything weird and you fail the visual inspection.

NuttyProfessor

We've already determined your M97 has a different SAI pump, right? And, we already determined the fuel injectors are different, right?

Are the scavenge pumps different? Does one of them have a brake booster on them? The M96 doesn't have that.

Thanks for clarifying what M97 engine you're implanting. I still think there are some notable mechanical differences between the two engines even though they share a lot of the same parts and have the same displacement. There wasn't a tremendous amount of power jump between the M96 3.6L and the M97 3.6L, but enough of a difference in engine management to cause the issues that you're experiencing. Seems like you got some good advice here on the forum. Hope you find a solution.

Rdrcr

That's what I did!

Mike

colmfmurphy

@NuttyProfessor I don't believe the oil pumps are different between the two motors but to be honest, I didn't really look hard at them. I will tho...

Yes, got some great info here and have done throughout my swap process so thank y'all for that...

I'll try to get in and under the car tomorrow and look for those differences you mention...

colmfmurphy

@Rdrcr as I said earlier, the much better half is glued into where we're at so no chance of that...

cds72911

In my opinion, you are just shooting in the dark unless you use a code reader to pull the specific codes and systematically troubleshoot them. Everything else here is just a guess. A CEL could even be for some unrelated reason, but you won't know until you pull the codes.

cds72911

lowpue, in my opinion, you are in a slightly different boat going from the 996.1 to the 997.1. There is a lot more work involved in that swap, as I understand it. The 996.2 and 997.1 are much closer from a wiring, engine management, and fuel system perspective. No doubt Dundon can help, but are they likely to share this information with someone who isn't a paying customer?

808Bill

You never know unless you ask. It's worked for me although I did offer upfront to pay for a little "tech advice" and was given (not Dundon) it for free.