My 1999 Toyota Camry whistles on acceleration, why?

This started to happen three four months ago. I had new tires put on it and the problem persists. I checked the air filter and housing and it looks good. The car runs good otherwise.

6 days ago
The check engine light is on and the local auto parts store says the code suggests something in the exhaust area, but the exhaust is calm.

may also be a leek in exhaust system.

Whistling is typically caused directly by moving air of course . that means it most likely isn't caused by the tires. usually whistling is an indication of a vacuum leak.

However, throughout acceleration, the vacuum in the engine is lower than at cruising speeds and deceleration, so that could be less probably to point to a vacuum leak. usually when the whistling caused by vacuum leak is probably to be noticed or louder is when vacuum is high, on deceleration or cruising.

However, I could check all the vacuum lines to be sure there isn't an evident crack or leak anyway. Also put the car in park and set the parking break, and somewhat speed up the engine and see if you may be able to hear the whistle while looking at the engine compartment. You may be able then to tell where it's originating.

Many cars have a vacuum line that goes from the intake manifold to the transmission. This goes to a sensor that detects dropped vacuum pressure when acceleration starts, and that tells the transmission to shift down into a lower gear for passing, etc . may be that there's a leak at the sensor, but that is kind of a stretch.

I could attempt the listening from outside the car 1st.

Vacuum leaks are a ache to find on occasion, but they're usually the because of whistles.

Does it whistle when the car is sitting still and you just push the gas? Just follow the sound, use a rubber hose to help find the sound, hold one end to your ear and the other around the suspected vacuum line.

Exhaust problems do not generally mean a deafening exhaust. If the code that's set indicates a malfunctioning catalyst, the sound may be inside the exhaust. If the catalyst is stopping up, it can come from there and set the code. I have seen so much back pressure in the exhaust that it blows out by the gaskets under load, but is calm otherwise. But typically that goes along with running problems also. You may also get a whistle from baffles inside the muffler if it's failing, typically under acceleration. Vacuum is at its lowest on acceleration and at its highest at deceleration and idle. If the sound is instigated by vacuum, it should be there at idle. My bet is the muffler, but I have to know what the code is.