The Tribeca is My wife's car, so it was taboo, until she drove my Toyota Corolla. Even she could "fell the difference!"(TM*) So , yesterday I had the chance to Groove the Subaru Tribeca (3.6 L, H6). I love electronic throttles! Less work , better response. There is one catch; "where do I cut the groove?" I use a Scanner to read the TPS (%)at Cold Start. For the Tribeca was 20% . So, after I took the throttle off , I positioned the TP (throttle plate)at an angle that matches the TPS($) reading. (Throttle connector ON, key ON, engine OFF)
Because the difference in diameter of the throttle body (TB), Ron's trick with the business card doesn't always work...and than you have idle problems... and you have to redo it. I believe my method will always work.
The results:more power , smoother run, quieter engine ( My wife said "it's like flying!), and a better MPG on her 50 miles daily drive . This car has an on board trip computer that shoed 18.6MPG average compare to 15MPG before the Groove! That is 24%! Pretty good for a half our work.
That's IT! I am going Pro!
Titus

GadgetmanNebraska here, I have a scanner and would like to know how you are doing this. After you find the cold start percent, are you moving throttle plate by hand, and looking at scanner at same time to see percent. Email me @ This email address is being protected from spambots. You need JavaScript enabled to view it. with specific details please. Thank you for the information.

WOW why not post this info for all of us on how to do this with specific details as well. Thanks

Titus, you are doing so well!!!

These reports go a LONG way to showing what can happen if you do it right. On this one, I suspect you can do better, though!

Next step, CHECK FOR VACUUM LEAKS,

Then, INCREASE SPARK GAP BY 20%.

Then, come back here and tell EVERYBODY ELSE what you find!

Check with Scott over at Major Muffler and see if he still wants me to come on the 18-19th. I'll buy YOU dinner this time!

Thanks for keeping the faith.

Ron

here is GadgetmanCA's post from another thread describing his method for setting the throttle plate position on an electronic throttle...

"On electronic throttles there is no Idle valve or separate way for the air. Now ,if you cut the groove the same way , you'll have a problem with idling. To avoid that, the groove need to be cut about 3/16 away from the TP. You can achieve that by putting a business card between the TP and TB (throttle body) on the opposite side . ( Ron's method) It works most of the time. Personally , I use a more precise method to establish the groove position on electronic throttles. On an OBD2 scanner, I read the TPS (%) value at cold start. After I take the TB off the intake , I leave the electrical connector on the TB , and key on/ engine off (how else?!), I mark the position where the TP matches the TPS(%) reading on the scanner. Some TP's get stuck once you turn the key to on position, so be creative, use different spacers before you turn the key on ,until you achieve the same reading for TPS(%).Once you get it, leave the spacers on and do the groove."

Karl Fortner
GadgetmanTacoma (youtube)