Wet/damp/faulty ignition wires, contaminated fuel (water), worn out spark plugs.
No, but bad spark plugs or plug wires sure can.
Your 1996 Pontiac Grand Prix will experience cylinder misfires when one or several of the spark plug wires are bad. A bad spark plug can also cause the problem.
POSSIBILITIES: Faulty spark plug - faulty ignition wire - distributor rotor needs replacing - distributor needs replacing. The most common cause of multiple misfires on the B20 / P75 engine used in the 1999 CRV is valve recession. this is a well documented problem on these engines. Repair usually requires replacement of the head.
incorrect engine timing so that it misfires
Several things can cause a Multiple Cylinder Misfire. First and most obvious are your spark plugs and wires. If they havent been changed within the last year that you can remember its time to change them. Faulty Crankshaft sensor would also cause this to happen but is unlikely.
The P0135 code indicates a problem with the oxygen sensor heater circuit in the upstream oxygen sensor. While this issue alone does not directly cause multiple misfires, it can lead to improper air-fuel mixture readings, which may result in poor engine performance and potentially contribute to misfires over time. If the engine is running poorly due to an incorrect air-fuel mixture, it might trigger multiple misfire codes. Therefore, addressing the P0135 issue is important for overall engine health.
Mechanical issue, ammunition issue.
Wiring and internal engine problems can cause misfires.
multiple/random misfires
In theory, it could, but in all practicality, it would not. The four main causes of misfires are faulty sparkplugs, bad spark plug wires, bad fuel injectors or a loss of compression.
P1399 is a pending code for random or multiple cylinder misfires.
Well, a code 43 is telling you that you have multiple misfires. The code 27 is a problem with your fuel injectors. Given this and the fact that you smell gas, I would suspect a gas leak at the fuel rail or in the line. Interrupted fuel supply would certianly cause a misfire.