Awhile back when I left 2 spark plug wires slightly un-plugged the auto kept wanting to downshift. So I plugged them in and problem solved..
But now its doing it again and I check all the plug wires and they are fine.
A guy told me that the plug wires could be going bad cuz Ive had them for 3 years.
is he over exaggerating?
Could it have to do with the new stereo I installed? I notice my sub makes a frequency noise and gets louder as I give the car gas..
someone help.
thanks.

 

After three years... Probably would not hurt to repalce them anyway.

 

plug wires can introduce noise and electromagnetic interference into your stereo.. and your vehicles electronics... which can also effect the performance of your car.

are your plug wires looking ratty... are they cracking.. 3 years is pretty old.
I'd replace them... will it fix your sub low freq interference... maybe .. probably not...

 

Don't know much about automatics but sometimes a bad vaccum line can cause wierd things to happen to trannys.

 

check the "transmission throttle cable" (the one that is located side by side with your throttle cable) make sure no tension has been put on it from the running of stereo wires or what-not...

 

if the motor is not making good power your throttle is open more that normal when cruising, there fore the automatic interprets this you're trying to pass and downshifts.