First time poster here, so please bear with me. Some mechanical understanding, enough to make me dangerous. LOL
I have a 2009 Smart, regular engine from what I’m told. Started having multiple codes for misfire on all cylinders. Smarty never had the plugs changed, currently at 150K+ kilometers. Took it to my licensed mechanic, he’s not familiar with Smart Cars but was willing to have a go at it. Changed all of the spark plugs, and checked coil resistances which pretty well matched each other. Things were OK for about a week, then started getting P0302
#2 misfire codes again – only P0302; nothing on the other 2 cylinders. Yesterday, mechanic swapped out
#2 coil with
#3 , changed out the
#2 spark plug again just in case. Out the shop door, but on drive home got the P0302 code again. And many more since, but only P0302.
Also, to add to this, the system two months ago started going into OL Open Loop (OL-FAULT then to OL-DRIVE), which I can reset by turning the engine off and then restarting – this will happen with and without a P0302 code.
For the
#2 cylinder misfire, it initially started happening while going uphill for a prolonged period, but will now code at level driving, stop and go traffic. In addition to the OL Open Loop at times.
Seeing that the plug has been changed (twice) and the coil swapped, I’m thinking along the lines of it’s the
#2 injector, but my mechanic says that injectors nowadays are fairly reliable. I’ve just put in half a can of Seafoam fuel conditioner into the fuel tank in the hopes that this may free up any injector problems while mechanic is researching.
Anyone with any ideas?
