Rep Power: 0

Have P0300 and all four P0301 - P0304 codes.

I have chased it down to a possible timing issue. The car does run rough at idle and has no top end power but the mid range seems to be fine. The valve spaceing on all checks out within spec.

While doing TDC checks during the valve spacing check the cam gear markings are off a tooth. I had a long flat head screwdriver in the spark plug whole and watched the TDC be off on all cylinders about 1 tooth. I can't make out the other marking on the bottom gear due to rust. I'm not sure if the previous owner did the job themselves and it's just a bad timing job but can I fix the timing without removing everything because I don't want to break it further. This would be my first time dealing the timing on a car and watching videos looks like a pretty aggressive job for a nookie. I would have thought the car would tell me if the car is off of timing since it has sensors... or am I chasing something totally off?

History: I bought the car with MAP code and IAT code and no other codes. once I replaced those sensors the car had more power (passed 3500 RPM) but then the misfire codes came around. Did the basic plugs and sparks replacement. Did a vacuume check and nothing is leaking. Compression check was within spec.
No over heating or bad oil. Did an oil change and did not notice any coolant or metallic shine in the Oil. Don't think it's a head gasket problem. Removed EGR and inspected it. Looked great probably newish, light carbon build up.

 
Rep Power: 127

Is your coolant reservoir overflowing? That'll indicate a bad head gasket. D-series engines are quirky and don't show the regular symptoms.

What kind of sensors did you get? Honda's don't fair well with aftermarkets.

What's the mileage? It may be time for a new timing belt anyway. If your timing was off, it would be in limp mode, which it does sounds like its in, which is why the code's returning at 3500rpm.

 
Rep Power: 0

It's high miles. 200k so I feel like it's time to replace the belt. Might as well do the water pump with the belts. The coolant is fine. Also checked that and forgot to post about it. Honestly all the belts look newish. I'm pretty sure it's a bad timing belt replacement job.

Got some Duralast sensors from Autozone.

 
Rep Power: 225

Usually the timing being off wouldn't throw misfire codes. Using a screwdriver instead of the crank pulley timing marks it's going to be difficult to tell if it's out of time. I know you said the marks on the crank pulley are rusted but I would want to be sure. Doesn't really matter if you're planning on doing a timing belt anyways.

A popular cause of misfires (on all cylinders) is clogged EGR runners in the intake manifold. Removing the intake manifold to check/clean is no quick fix though.

 
Rep Power: 0

Is there a quick test to see if this is the problem?

 
Rep Power: 223

Check if the car has EGR. If it does, with it having 200k it's pretty likely that there's some junk in there

 
Rep Power: 225

Pulling the intake manifold is the only way to know for sure if the runners are clogged.

 
Rep Power: 134

Use only the NGK OEM spark plugs.

 
Rep Power: 0

Misfire is now gone. But now i have a new problem to find. P1505. I have replaced the PCV already so now on to hunting for a air leak.. or a bad IACV?

 
Rep Power: 223

Did the new intake gasket have the holes for the EGR?

 
Rep Power: 0

Yes the misfire is gone. The vaccume leak is gone... but now I'm getting high voltage out put from the MAP... still haven't done the timing. Pretty sure it's off and giving me back pressure.