So I just left work this morning and I feel like I've lost some power and the engine is loud when I push full throttle it sounds like I have an intake and piping done it to but its fully stock. Could it be my catylytic converter went out? Any ideas on what it might be? And if any1 in so cal might be able to check it out let me know thanks oh by the way I have a 2002 is300.

 

Any CEL( check engine light) comes on? Or the car just stumble when you step on gas. If so, sound like you got a bad air flow meter( located at the air filter housing). Sometimes, it will not set any code(CEL), but I've seen so many of them go bad.

 

With the vehicle off, pull the EFI fuse (found in the fusebox in the engine bay) for about 10 seconds, put it back in and then drive the car for about an hour with 50/50 mix of city/highway. Sometimes sensors can get funny reading that run the vehicle into cow mode (I know this all to often at my altitude).

Other thing as VVT-i mentioned is a dirty MAF. Now one might think one would notice something over time, but if the MAF reaches a threshold in terms of the crud on it, it can cause some issues even withthout a CEL getting thrown.

Other thing could be ruptured hose, perhaps one connected to the airbox. Also check your air filter.

 

Hey guys I took it to a shop the check enginel light was on and they codes that went off was the o2 heater sensor was bad and the 1st catylytic converter was bad. The car only has 50,000 so I took it to the dealer to have it checked out. I heard federal emissions law was 8/80,000 miles is that true? Thanks for the help

 

That's correct about the federal emissions warranty.

It would not absolutely surprise me on one of your precats, since one of mine went dead down here from bad gas, but not the O2 sensors, they are the same original ones. However, I would love to see the code first, since there are a few that do signal a bad O2 sensor.