I am planning on purchasing a VoodooII kit for my 2000 miata. I have read all of the threads about the Voodoo Box not being the optimal fuel management solution and would prefer to go MSPNP. My dilemma, I live in a state with annual OBDII checks, MA. If I choose to go MSPNP can I install the stock ECU back in the car with a mechanical lockout to force the wastegate to stay open so that I do not generate boost for the 1 day of the year that I have to go get my state inspection sticker? The test station only reads the OBDII status and verifies no CEL. Would running the stock computer and running 0 boost potentially damage the engine in any way? I will have to run the car for 10 - 50 miles for the OBDII test to complete.

 

I'm not going to comment on possible damages to your engine, but for those CEL tests.

In my area (Ontario) you can fail the test without a CEL light on if there aren't enough miles on the computer since it received power. Comes up as 'not ready', because it hasn't yet gone thru a drive cycle. This is to prevent people from disconnecting the battery to clear the codes and then getting tested.

I'm not sure how long a drive cycle is on the miata, it varies by manufacturer, but you maybe be looking at driving more than 10-15 miles just to get the computer ready to test.

 

You should be able to open the wastegate and swap the stock computer back in for testing, but you will probably also need to swap the stock injectors and any coils or other items that you've significantly altered back to stock. You will also need to retain the EGR system.

My approach is to run the MegaSquirt in parallel to the stock computer, letting it control fuel and spark with timing and fuel similar to stock when out of boost, but keeping all the emissions equipment in place and letting the OBD2 stay happy. I had it working briefly with the MS1, but wasn't happy with the somewhat rough tuning limits. Now I'm preparing to get it running again on the MS3Pro.