Manual CSX RPMs Suddenly Increase
 

I bought a pre-owned 2010 Acura CSX a few months ago. It's my first manual car and so far I absolutely love it. However, it suddenly started acting strange a few days ago and I'm not sure if it's normal or not with a manual transmission.

I'm finding that the car is really touchy with the gas now and will suddenly shoot up in RPMs at even the slightest tap, regardless of the gear it's in. I could be cruising along comfortably in third at 3000rpm then if I try to accelerate slightly, it will jump up to about 5000rpm. Sometimes it will drop back off on its own (usually rather suddenly) and other times I have to let up on the gas to get it to mellow out. It's a very uncontrolled increase. I have to be cautious while doing city driving as sometimes it gets a little too eager when I tap the gas to accelerate slightly.

It's doing this in every gear from 2nd to 5th and guzzling gas like a monster. It is kind of nice having that sort of response from it when I need it, but I'm just wondering if this is normal or if I should take it in to get checked out - and what could the problem possibly be?

It has about ~40,000km on it and I just had it in for a service (oil and filter change) last week. I let someone borrow it on Friday and ever since then it has been doing this.

Any help is greatly appreciated! Thank you.

Seems like someone had done modification to the performance of this car. Best to get it tuned by a dealer..