My 2000 mustang (5 speed manual) has this very confusing issue and I need help. When it is fully warmed up and its a relatively hot day outside my car does this thing where if I give it medium to hard throttle it'll stop accelerating at like 2500 rmp and start bogging and slowing down (the more throttle the more it slows down) so i have to accelrate very slowly in order to move foward. Eventually it'll get to the point where I can't get it moving forward in first gear. When I shut off the engine there is this indescribable horrible smell from inside my car that I can't seem to trace to anything. It's almost like a sweet mettalic smell but it is terrible. I have no engine lights or pending codes and I've cleaned and checked the MAF and IAT sensors and they seem to be fine.

 

Try the other standard running trouble items, fuel filter change, run a bottle or two of fuel filter cleaner through, change the spark plugs, etc.

 

It's got a new fuel filter in it and I've ran sea foam in it and it still acts up.

 

has any thing else been done to the car in question? tune up, oil change, ect? has the car sat for a long period of time at any time? are there any odd noises coming from the car as your driving, idleing, or shifting?

 

May want to take a look at your cats if they are starting to get plugged up it will bog and the PCM goes into failsafe mode causing horrible acceleration.(although that should at least have a pending code associated) unless its the beginning stages. Cats that get extremely hot (from being clogged) can cause smells like you described and being an older car It probably has a little road grime and or stray fluids underneath anything could be burning off causing that smell.

 

Do you have an OBD reader? Look at the live data and see if it is Fulal or air causing this.

 

No recent tune-ups but I put oil in it recently and its a daily driver and no odd noises until it starts acting up. There's a clunky back-fire type of noise when it happens

 

Tested my cats with an OBD 2 reader and they were fine. My friend suggested it might be an 02 sensor when it goes into open loop and that its telling the car to run lean causing it to bog and heat up the cats