Loud exhaust My 2003 corolla is making a staring noise. It sounds like its coming from the exhaust. Every time I press on the gas it sounds like its struggling. It's only been getting worse. The car has 170k miles on it. I recently changed the oil and was told I should change my transmission fluid soon. Also, the engine has recently started making a clicking sound. Any idea what may be causing this problem ?

SOURCE: 1991 Toyota Corolla loud and sluggish

You need to do a compression test on the engine cylinders. It appears one of the cylinders is not firing and dragging the rest of the engine down in power. The compression test will show if one of the cylinders has a problem.

SOURCE: Loud annoying sound when driving over 35 mph

Check the fluid level and make sure. If the fluid level is not the problem, I would have someone do a complete check on the front end.

SOURCE: 2002 corolla (now 91000 miles) makes rattling sound

Thats good that you are getting a second opinion. A Toyota dealer will be able to check it and see what the noise may be. See what they come up with. I dont think a worn timing chain or guides would cause a low oil pressure problem. But, if it does indeed have low oil pressure, that is a serious problem.

SOURCE: Engine sound when speeding up

the problem you are describing sounds like you have a loose rod bearing which is common on a engine with that many miles on it and under excelleration yes!! it will knock with it knocking to that degree for any lenght of time! putting new bearing in won;t fix it!! cause damage to the cracnshaft has already arose you will need to pull the motor and change the crank and bearings or replace the motor

SOURCE: Frequency to changing transmission fluid on 2003 Corolla

I'm not sure about Toyota's specific recommendation but when I ran my service station, we changed trans fluid at the 50,000 to 60,000 mile range. This covered most manufacturer's requirements at the time. Hope this helps.