Hello! I currently drive a 4 cylinder 1999 Honda Accord coupe and ever since I purchased the car, it had issues with its acceleration. When I begin to apply gas, the car begins to accelerate, yet it hesitates and acts sporadic. The issue is mainly at low RPMs and after checking the codes for the check engine light, I was told it was the Idle Air Control. I then replaced it, yet to no avail, and the car remained the same. I am unsure if it is because of the TPS or voltage issue but I would like some assistance please! Thank you all!

 

I'm confused about your mention of TPS and voltage issues. If you have an issue with voltage or the TPS that can most definitely effect your acceleration, throttle response and ignition.

What were the codes that they pulled from the ECU?

 

Those were a couple of solutions I saw possible, I was wondering if there was a way I could pinpoint the problem rather than purchase several additional parts. I ran the codes and saw that I had encountered the P0505 code, which has to do with Idle Air Control. I then replaced the Idle Air Control Valve completely but it remained the same.

 

IAC, deals more with warm up idle and stop and go idle then acceleration.

Some stuff you can do for free would be
PCV, EGR throttle body cleaning
Check your spark plugs

When was the last time you did a full tune up? Plugs, wires, distributor cap and rotor, air filter..... NGK plugs are a must.

Do you know when the last time the timing belt replacement and valve clearance/adjustment was done?