Hey guys,
Ive been creeping around different forums looking for a similar case to what my Hondas experiencing. I was hopeful you guys might be able to assist.

I have a check engine light for all four cylinder misfires and a generic misfire code (P0300-P0305)
however the CEL doesn’t start immediately, the car runs perfect for around 45 -100 seconds after startup, then engine light comes on while using any throttle at all and goes away when the car is at idle.

It’s now like clockwork if I restart the vehicle I’ll have less than 2 minutes of smooth operation. If I try to drive the power is severely limited with a top speed of 20 mph.

The car has all new of the following,
spark plugs
coil packs
both cam sensors
battery
water pump (hopefully not affecting my issue)
and fresh 93 octane fuel just in case.

Ive read on the forum that the Cat might be clogged, but I’ve removed both o2 sensors and same thing’s happening.

if anybody has any insight it would be greatly appreciated

 

Can that scanner read short and long term fuel trims?

 

So when I restart the car before the engine light comes on the short term fuel trim is between -10 / -18 as soon as the engine light comes on it drops to 0 and never moves,
Also the long term fuel trim never moved from 0

 

The total fuel trim is the sum of the 2 numbers, so your PCM is detecting a rich condition and injecting less fuel. What does the mass air flow sensor show at idle before the CEL turn on?

 

0.5 lb/min before the misfires

0.3/0.4 after cel comes on

”edit”
I’m looking at my intake manifold pressure and it’s only At 7.5 inhg, this seems low to me. Any chance this could just be a map sensor ?

3rd edit
I believe I found the issue,
when I recently had the clutch changed the mechanic also added a lightweight flywheel. From everything Ive read you have to flash the engine when adding a lighter flywheel or you get misfires for dayz.

Also it looks like if I go with the reflash option I won’t be able to get my car inspected. I’m not sure how accurate that is but I’m not going to chance it.
new OEM flywheel and clutch on the way

I hope this helps folks in the future.👍🏼