I have the same thing. I had to adjust the idle screw just to keep it from dying.

 

I am tuned and have been for almost a year so I doubt thats the problem

 

Clean your tb.

 

A co-worker of mine recommended spark plug cable replacement as Im at 80k and 6yrs. Might give it a try if I can find some cables online.

 

Well cleaned the throttle body today with Valvoline's Carb/TB cleaner and no luck. Still have the strange lope present.

Getting worried it might be the IAVC, at least I think that's what its called. Anyone know of a good way of checking this before I drop 400 on a new one?

I also noticed when my idle drops about 100-200 its typically when my engine fan kicks on... Not sure that means anything, just an observation.

 

Iacv is not $400 more like $40-70

 

where? the cheapest i found was the mikuni from parts geek and that was $288 and change. the tps was cheap though.

 

datalogs would help too

 

The code my car threw was a EGR flow. Just waiting for a new egr valve and solenoid to arrive. Hopefully this fixes the problem.

 

Well time for another update...

Car threw a CEL...

P0453, P0450, P0300

Im guessing whatever is causing the P0300 is my idle problem but not sure where the P0453 and P0450 came from, although they both point to the evap pressure sensor.

Im going to search the forums to see if anyone else has had this same combo of CELs.

 

P0300 from cams or too much timing/lean at cruise

evap means you have a gas leak somewhere ... Gas cap, fuel return hose, evap canister, evap solenoid...have you done any major work to your IM?

 

Could the lean be caused by the gas leak by chance?

Awhile back, about a year ago, I was rear ended and had to get the entire rear end re-built. I believe I had a check engine light at that time as well that was related to the Evap Canister (Code P0455). The canister got replaced and my rear repaired with no issues in the past year.

All these headaches I'm having now started shortly after I completed my TBE install.

 

After checking the Service Manual Ill probably try to veify the cause of P0453 and P0450 by first checking the voltage level across the fuel tank pressure sensor.

I'll post what I find...

 

Still trying to track down the cause with no solution. I have a Noon appointment with the local tuner here Saturday in hopes he might be able to help out.

I'll post any results we find... Hoping we can solve it and I can get tuned finally

 

new egr valve and solenoid and now my car is back to normal.