Power loss mid rev range

[Blut_VTEC]

I have a 2003 Accord Type S which has a significant power loss in the mid rev range (4000-6000 rpm)
I own a couple of these Accords and I know this is not right.
low rev and VTEC work good , so does the idling. engine runs very smooth
In the first 2 gears its driveable but in 4th gear around 5000 rpm , you can get give full throttle but it's not going. When u shift up and get around 3000 rpm you get accelarate to 5000 again and then it won't climb anymore .

I don't have any error codes
I've did a compression check, all 180 psi, so that's good
oil is good.
changed the sparkplugs and coilpacks.
changed the airfilter.
opened the ECU, no damage.

Any suggestions ? I thought maybe a clogged up catalytic converter but then again, after 6000 it's accelarates fine again.

 

[F6HAD]

Check your timing hasn't slipped

Also have your valve clearances set again

 

[Andyjdmteg]

Didn't realise how flat my old type s was until the clearances were adjusted, made a hell of a difference (clearly hadn't been done before on 70 odd k)

 

[Blut_VTEC]

cleaned the VTC strainer and the VTC spool valve .
And also change the crank sensor and tdc sensor from another K24a3 I have laying around here.
Didn't made a difference X(
Tomorrow I'll check if the timing of the chain is correct and check the valve clearance.