I have a 2008 CR-V. I had my alternator replaced by a local Honda dealer. I got it back and realized that while my CR-V was in idle it would shake/stutter as if it were about to die but start up again. Outside the vehicle, while the stuttering happened, you could hear a click and a revving up sound. It never did this prior to the alternator being changed. I took it back and the mechanic at the dealer claims they heard/felt nothing wrong. I had it back a day and it still did the stuttering thing but now the check engine and VSA lights came on and my vehicle put itself in limp mode where I can’t go over 25. I had zero issues before having the alternator replaced. I called the dealer back and the tech said this issue has nothing to do with what they did but again all this started after work was done. Don’t know if this is a coincidence or if they didn’t assemble something right. Any ideas would be greatly appreciate. Thanks!

 

Get the car scan for trouble codes (actual number codes) and post them. Many auto parts stores will read the trouble codes for free. They will need to have an OBD scanner/reader capable of reading Honda VSA/ABS codes; most stores will have it though.

 

It sounds like its loading the engine up when the AC cycles ( click of the compressor engage and whirring of the condenser/rad fan). These both put loads on the engine that can drag the engine rpm way down. The engine idle control should respond as the ECU calls to raise the engine idle to compensate to the load increase..mechanical load from the compressor and electrical load of the fans as seen by the alternator load sensor.
I haven't done this repair myself but it sounds like something wasn't fully connected or not connected at all, however they should be forthcoming if they found the issue.

 

Kinda sounds like they messed something up. either the belt isn't on correctly, the alternator is faulty, or someone didn't make sure all the connections were tight. "Nothing to do with the repair" sounds sus af lol. Although it's been a week, and OP hasn't said anything.

 

This is never good. At some point you want to drop any semblance of being polite. No doubt you' ll get some man-splain bull stuff. Take a look under hood, check connector plugs, check belt tensions, should be tight, but a bit less than a banjo string. Look for any thing out of place, loose hoses, etc. You may want to contact Honda corporate, though it may just be a waste of time.