I purchased a used '06 Chrysler Sebring Touring Edition (V6, currently has 34,000 miles) back in November and have been a little bit disappointed with performance. The car starts on the first attempt every time, but seems sluggish to turn over. After starting, the engine runs very rough for about six seconds and then levels out, although idling rougher than past V6 and even 4 cylinder cars I have owned.
The accelerator pedal is also rather loose, traveling very close to the floor even while cruising at highway speeds. I replaced the air filter with a K&N filter and replaced the OEM Goodyear tires with some performance Yokohama touring tires - much smoother ride and improved acceleration but not what I was expecting from a V6.
Is this just how a Sebring performs? Any suggestions on how to improve performance? New plugs, perhaps?
It could be many things. However I would suggest starting by checking to see if any error codes have been stored in the computer. Some auto part stores will do this for free. Try Advanced Auto Parts or Autozone.
Note: K&N air filters may give you a little more power, they are not without their down sides. You need to oil them when you clean them. If you get even a little too much oil it can damage some sensors in some cars. I don’t know if yours is one of them. This might explain the roughness, but I don’t see any connection with the accelerator. Modern cars have well designed intake and exhaust systems, so as long as you have a stock engine, there is little or nothing that you can do to improve power in the intake or exhaust systems.
Note2: You did not indicate, but if the owner’s manual recommends high octane, you do need to use it or you will loose power and in some cars you can cause damage.
If you still have the original air filter, try it to see if there are any changes to performance. Pull a couple of spark plugs and look at them. If they look questionable, change them. You could have a mechanic look at that gas pedal and linkage to the engine (I hope it’s not a “fly by wire” throttle control).