Our TL has about 84k miles, and recently - last week or so, we noticed the car is randomly misbehaving. The first time the issue happened, we got a check engine light that cleared after stopping and starting the car again. The problem seems to be that as we slow down and when we are at the full stop with the brake pedal firmly on, the RPMs keep bouncing, and the car 'feels' as if it is almost rocking - front and back because of that. The first time this happened, the symptoms were very violent and scary and exibited before we weren were stopped. Now, the issue is still lingering; the 'rocking' feeling is much much milder, the RPMs don't jump; instead, they drop low to, let's say, 600 - 650 rpm and the check engine does not come on.

To add more background to this, we were on our way back from Colorado the first time this issue happened. We thought that perhaps the car freaked out after re-adjusting from the higher altitudes or due to the crappy gas. We didn't have any problems when driving the car out there (we stayed there for a week), and we went to 14k+ feet, no problem. We usually fill up 93 at Costco, but when we were in Colorado, we were at the mercy of whatever was available, usually 91 at best.

Any thoughts on what this could be, any recommendation for a good ODB2 reader? I want to be prepared to grab the codes when the check engine light comes on.

 

Hey there,

Hopefully another member can chime about the best scanning tool. As an FYI, I typically only use Sunoco 91 (93 once a year maybe) in my 2012 base TL and have since new. Just about to hit 90K and have never seen the CEL or had idle issues. Hopefully a bad tank of gas?

Good luck!

 

check your charging voltage make sure its 14.4V and is charging. Get your battery tested at auto parts store. That is a classic symptom of idle issue. Also were you running the A/C? If there is a problem with the A/C system, a long trip may make it appear and the engine has to work harder for the A/C system.