Low boost and misfire at high rpm

Well a little stumped and figured may as well ask for some help before throwing parts at the car.

 

Car is an 01 legacy b4 rev c automatic. Primary downpipe and center pipe decat. Dw65c fuel pump. Zerosports intake pipe with apexi filter. 3 inch catback.

 

Just got the car back from being dyno tuned yesterday (Friday). Tune was finished on Wednesday. Was tuned using project lambda open source.

 

It was raining insanely hard yesterday on my drive home which is about an hour away from the shop, so I didn't get much chance to boost it or anything. But before getting on the Highway I did a quick 1st to 2nd Wot and it was fine.

 

After I got off the Highway I filled up the tank and headed home the rest of the way. Car seemed okay til I went to go wot again and it was boosting low around 7psi on primary and 12 on secondary and misfiring at 6k as if it was redlining.

 

This morning it was still wet out but the car boosted 10psi on primary and 14 on secondary but still misfired at 65k this time.

 

Looking for any suggestions. Theres no codes or CEL and Like I said the car didn't do it for the tuner and didn't do it until after all the rain on the Highway and after I filled up.

 

Gas mileage was amazing on the way home yesterday as well. 100km and barely moved the hand. Since the refill have done 30km and it's moved a whole notch.

 

Vacuum reads fine, and the car drives fine other than lack of power and misfiring.

 

Thinking maybe a wet coil pack that's on its way or maybe even a bad batch of gas. Plugs were changed around 20-30k ago with ngk pfr6b plugs

 

Thanks!

Check the gaps on your plugs or change them out for one step colder plugs. I would have put new plugs in before the tune to insure even ignition across the engine. Also check the couplers you could have a boost leak and your tuner should be able to boost leak test it. Edited June 26, 2019 by RumbleRumble

Check the gaps on your plugs or change them out for one step colder plugs. I would have put new plugs in before the tune to insure even ignition across the engine. Also check the couplers you could have a boost leak and your tuner should be able to boost leak test it.

 

They did a boost leak test before the tune, but I made sure all the couplers were good. Have ordered new plugs and coilpacks so hoping that solves the issue and went a step colder for the plugs.

 

Probably should have changed them out before the tune but forgot about them and figured they would be good.

 

Tried switching to a new maf sensor where i have a few but that didn't change anything. Coils and plugs are set to come tomorrow so hopefully

Subaru plugs regardless of type (copper,platinum) of plug should really be changed every 30,00 maybe even sooner.

Subaru plugs regardless of type (copper,platinum) of plug should really be changed every 30,00 maybe even sooner.

 

Well just changed out the coils and the plugs to a step colder with the ngk pfr7b. And my issue is still persisting. Car did feel a little smoother but still only hitting 10psi primary and 14 secondary and misfiring at 6500

maybe something is up with your tune and the timing maping is off or something along the likes

maybe something is up with your tune and the timing maping is off or something along the likes

 

Well finally figured out the issue the other day. Had another tuner who did etunes for me last year look at the map. They lowered my boost and the redline by accident to 6500rpm. So he adjusted it for me. I contacted the shop and let them know and they kind of played it off as i should have known they made those changes.... Well no if you dont tell me that I won't. And they could have tols me when I first contacted them instead of blaming it on mechanical issues.

 

Car works good now that i know the boost is lower and that the red line is back at 7k. Only issue is the idle can get rough occasionally. May be that its just relearning since the battery has been disconnected a lot due to trying to find the issue and resetting the ecu. Only happens every once in awhile and seems to be getting better