Exactly, a hiccup, now that the weather cooled down it does rarely. I did check the vacuum hoses around throttle body, looked good to me. I will run a vacuum leak test just in case as well

 

I had my car out at autocross on Sunday and it was around 100 degrees outside. The car ran great and I had no issues. Now, I did recently change the front OEM Intercooler on the car to another OEM one and secured the hose clamps and it runs way better. I still hear what I think is a vacuum leak and need to try and sort it out. I was about to order spark plugs but mine only have maybe 2,000 miles at most.

 

What was wrong with yours to change it to another OEM one? I still have no issues while engine is cool or even when it gets to working temperature, weather cooled off as well, so even if i push on it, it does the hiccup a lot less compared to summer time. I still need to do the same, and run that vacuum leak test, before i spend more and more to figure it out..lifters,valves etc. Its funny how a lot of 9s have similar behavior when in stock condition. Btw my plugs are new as well 4-5k on them, last time i took them out looked good to me, color was the same on all 4 of them, little brownish nothing crazy..i am still not sure if i have to gap OEM plugs on stock engine..when you put the exact OEM specification, i doubt they gap plugs in any dealership if anyone took their car there at all lol

 

 

My Evo has had a miss as stated in previous posts. When I did the inter cooler swap and tighten the hoses it runs better than ever. I had to have had one of them lose I'm guessing. Under load my car feels amazing. Checking the gap on your plugs is a good idea anyway if you don't know the history of the car. As you mentioned I boost leak test seems to me a must do check up with these cars. They happen and can happen often.

 

I see what you mean now and it makes sense. What i didn`t get is , why did you change the whole inter cooler with another OEM one if the problem was the hoses? Sparks in my car are new, 2-3k on them, but will check the gap anyways. I am looking for a place where i can do a boost leak test and maybe injector cleaning at the same time, and see what happens.

 

 

Maybe the the OEM wire need to be replace, I would say upgrade to COP it will run as if the car was brand new! when I did mine it was day and night. Those wires run hot !

 

I have a IX that has had intermittent misses at times. Always at idle or at light throttle. COP did not change anything. What seems to work is adding a bottle of methylhydrate to the fuel which suggests that this may be attributable to water contamination in the fuel.

 

I was actually about to borrow COP from buddy of mine,his 8 is pushing 700-800 whp so it should do it for me if it works for his car. idea is just to drive a few hundred miles and see if there is a difference,i will share how it went.. Another thing i just did was to check the hoses/clamps of my inter cooler , as @Wanted EVO IX stated. They all looked good to me, except the bottom one of the passenger side. Clamp is tight but the actual hose looks like its a little behind the pipe`s marker which could be fine, problem was that there was a little oil residue right after/outside the hose, i know that`s normal since i do not have a catch can..what i think though is, if an oil can go though that gap , so can air. I just had the car up on the oem jack so did not want to risk un/re-doing that clamp and not be able to put it back together since i wouldn`t be in a strong position to do so. Would you suggest that`s a boost leak red flag ?

 

Yes definitely, if oil can leak out so can air. You can grab ramps pretty cheap if you don't have jack stands and they are good for most things that don't involve removing the wheels. You can make a boost leak tester for <$10 from stuff from home depot, trust you will find a bunch of leaks.