Hey guys- So I can't tell if the issues I am experiencing are tune related or mechanical. (can move thread if need be) Sorry for the novel!

Here is a little background info... I successfully installed a Yank SS3600 and a 228r cam several months ago without any issue. After having the car tuned by a highly reputable shop in the Chicagoland area I was experiencing the following issues...

- high idle 1100-1300 RPM until reaching a dead stop. (drop to ~900rpm idle)
- Car took forever to slow down. (anything below 45mph) Felt like the cruise control was on all the time.
- Car wouldn't slow down even when trying to engine break. (in D or 2nd)
- Extremely rough idle, shook more than normal for mild cam. Wasn't that rough on first start up after cam swap. (stock motor mounts still)
- Major jerking/bucking when maintaining speed immediately after the converter locked up. (46mph)
- Car surged and stalled only when in reverse while backing down my driveway. (10* decline)

I spoke with my tuner and brought the car back in for some tweaks to the tune. After some adjustments all of the issues I was experiencing seemed to have been resolved, other than the odd surging/stalling in reverse when backing down a driveway. (weird..??)

A few day later while driving to the gym and after a few fun WOT pulls on the way there the car seemed to be fine. That was until after coming out of the gym and firing the car up (semi cold start)...then ALL of the issue came back, including a few more, on the way home.

What I'm experiencing now:

1) Again, anything under 45 mph the RPMs are sticking around 1300 until dead stop.
2) Car won't slow down past 20 mph and contently feel like I am fighting the engine from maintaining speed.
3) When maintaining a speed between ~25-50 mph the car sounds like it is surging but the RPM are visibly stable. The exhaust note sounds like a fat kid gasping for breath after running a mile.
4) From a dead stop at the bottom of my driveway the car will pull itself all the way up into the garage.

I have checked for vacuum leaks, checked/cleaned the IAC, TPS, and MAF sensor and everything looks clean and in working condition. (car has ~60K miles and has never seen snow and rarely rain) All my O2 sensor were changed 2 years ago during the header/full exhaust install. (4K miles since then)

Does this all sound like a tune issue or some sort of a mechanical problem. Everything was great but after a few WOT pulls and a cold start the car has been a headache to drive and hate driving it. Any thoughts?!?!

Thanks so much in advance guys!

 

Usually those issues are easily fixed with tuning.
However, if any issue comes back after it was fixed with tuning it means the problem is mechanical/electrical and the tune only patched it.

It's hard to give a diagnostic over the internet, but yours seem to be a mix of tuning/mechanical problems.
Look for vacuum leaks, change the plugs and make sure all injectors are clean.

If you didn't have any of the issues before it was tuned, then the answer is obvious. If you didn't drive the car with the previous tune and you don't know how it ran, you will need a lot more troubleshooting to fix everything.

The easiest way to know is to go back to a known-good older tune and test.

 

Sounds like a tune issue to me. I just had my car re tuned after some mods and now that it's colder out the idle is acting funny. Hangs at 1800 few seconds then falls to 950 once I stop. I'm going to drive it a little more or even address the issue when it warmer next year lol.