SaabCentral Forums banner

1 - 3 of 3 Posts

·
Registered
Joined
·
31 Posts
Discussion Starter #1
Hi everybody,

I have had a misfire issue on my car for quite some time. It hasn't gotten better or worse and the car keeps chuggin along. The misfiring occurs when I press the throttle 50% or more. The car then shudders pretty badly. I was getting acceptable MPG, SID usually estimated around 21 average. Now out of nowhere I startup my car one morning and its shuddering at idle and at any throttle position. The shudder at idle is more subtle. My gas mileage dropped to an estimated 13 MPG. The shuddering fluctuates day to day but always occurs at 50% or more throttle. I have the following codes currently, P0300 multiple misfire, P0302 cylinder 2 misfire, P0137 Bank 1 Sensor 2 Oxygen sensor low voltage, and P1312 which I read has to do with fouled plugs or the ionization module. My guess right now is the bad 02 sensor is throwing off fuel trims and the car is burning too much gas. Any thoughts? Thanks guys!
 

·
Registered
Joined
·
916 Posts
Misfire under load is likely a bad coil. Although with the way your car has been acting, new spark plugs would probably help too. Cheap insurance.

Check this thread to make sure you get the correct coil for cylinder #2. Maybe consider replacing any others that don't have the OEM Mitsubishi-Saab branding exactly like pictured.

http://www.saabcentral.com/forums/showthread.php?t=535961

Bank 1 Sensor 2 is the downstream oxygen sensor. It only reads catalytic converter efficiency. Prolonged rich conditions due to misfires or other issues can reduce the life of the sensor and/or the catalytic converter. Consider replacing the O2 sensor first since it's cheaper, clear the codes, and see if it comes back. If it does, then it's time to look at replacement catalytic converter options.

Other things that can affect fuel mileage (other than your car's obvious issues) include improper tire pressure and a dirty air filter. Check both of those.
 

·
Super Moderator
Joined
·
8,724 Posts
replace coils (see coils sticky) p03** codes will go along with the p1312 code..P0137 code will more than likey disappear due to the fuel being burnt properly and not the unburt fuel which is being dumped into the cat atm due to the misfires..
 
1 - 3 of 3 Posts
Top