Miss on acceleration
 

My 2008 ls has developed a miss on acceleration and gas mileage if off 25%. To start in the morning takes 3 tries exactly. Has 80k. Plan to change plugs and would welcome any ideas as to cause.
Thanks
John

I would get the codes read. If there is a misfire then there should be a code that will tell you which cylinder it is.

Code is for random misfire

There are a lot of things that can cause a random misfire.

There is a tsb for carbon build up causing a random misfire on the 2.4 engine.

I would start checking the basics. Fuel psi being my first test.

Shall I assUme that means ONLY p0300? That's pretty rare.

Fuel pressure is a pretty good starting guess.

If it's a random mis-fire and as donbrew mentioned above, could I suggest a Fuel Pump/Filter?

May I concur with these suggestions and throw in a dirty throttle body! Or battery about to expire! Or loose ground wires! The infamous low oil level?
Please check these suggestions and get back to us.

How many miles on it?

Good suggestions especially interesting fuel pressure. Has 80k.
Thanks
John

I see from searching the forum several cases like mine where the fuel pump was the cause. I will go get the codes read and try to get a test gage for fuel pressure. Is there a fitting for this on the fuel rail?