Sluggish acceleration

We just brought our 2005 Mazda 6 (v6) in for an oil change and now it’s very sluggish accelerating form a stop. It hesitates and has low power at slow speeds.

To complicate matters, I added a can of STP on the same day as the oil change. Could this have something to do with it?

The can of STP likely has nothing to do with anything.

Who changed the oil? If a quick lube place they could have fiddled with the air filter box as they typically pull it apart in an attempt for an upsell.

Also have you checked your auto transmission fluid?

Jiffy Lube did the job. Haven’t checked the trans fluid, but will do that.
Will a loose air filter box affect performance?

“Jiffy Lube did the job”

Well, that confirms my suspicions.
As Andrew noted, the first thing to check is your air filter box, as the poorly trained kids at J-Lube may not have secured it properly after taking out your air filter in order to try to sell you a new one. Or they may have disconnected a vacuum line. In addition to the drop in power, is the engine idling rougher than previously?

As Andrew hinted, it is possible that those lunkheads drained the transmission fluid
rather than the motor oil. The result would be a transmission that is very dry (some fluid is retained by the torque converter, so it would not be totally dry), and an engine that is grossly overfilled with oil (the old oil plus the new oil). An engine that is grossly overfilled with oil will be sluggish, and is experiencing damage from the overfill. A transmission that is grossly underfilled will shortly be a fried transmission.

In case you think that this scenario is not possible, I would estimate that at least 10 people per year report that exact situation on this site, and in almost every case, it happened at Jiffy Lube.

Since the result of an overfilled engine and a drained transmission=severe engine damage + severe transmission damage, I strongly suggest that you check the dipstick for both the motor oil and the trans fluid before you drive the car even one more block. If you find this worst-case scenario, have the car flat-bedded to a Mazda dealership to have their findings documented, as you would need that for a lawsuit against J-Lube.

Hopefully, you will luck out with just an improperly assembled air filter box, or a disconnected vacuum hose. For your sake, I hope that this would be the only screw-up that took place at J-Lube.

However, this experience should be your wake-up call to AVOID these quick lube places. They make a huge number of mistakes, and they are not even that cheap. Yes, they allow you to get in and out quickly, but most car dealerships will do a “while you wait” oil change if you make an appointment, and with the typical dealer coupon, they are no more expensive. Truthfully, the only advantage of a quick lube place is that they clean your windows–which is probably the only thing that they are qualified to do without screwing-up.

another thing is, that they may have cracked the hose between the manifold, and the throttle body. a loose air filter box could be it too.

either of those would cause the engine to run lean erraticly. if it was between the throttle body and manifold, the throttle body cant measure the air going in, resulting in over lean A/F ratio = hesitation, nearly stalling, and little low end power.

silicone and electric tape will work better paying cash for a new one, then waiting for the parts to come in.

Thanks for all the suggestions! Hopefully it’s something as simple as the loose air filter box. That’s my sense.

No matter what it turns out to be, AVOID those quick lube places in the future.

While Jiffy Lube is the best-known quick lube, there is another thread currently, regarding a Valvoline Quick Lube place that added motor oil without draining the old oil from a Mercedes E-Class sedan. The result was a grossly overfilled crankcase and likely engine damage.

Going to any quick lube place is just an invitation for problems, IMHO.