Hi,
Doe sanyone know if an exhaust sleak at the cylinder head will affect my gs mileage? Right now, I'm experiencing real bad mileage, say 13 mpg around town with easy driving, this is after new plugs, etc.

 

exhaust leak at the head??? at the manifold maybe?

 

A leak at the exhast manifold will cause a decrease in power output, so that will probably also affect full economy. damn dude 13mpg, somethings wrong, maybe leaking fuel injectors, You should first have the 02 Sensor replaced that will make a big difference.

 

yeah, when my y pipe rusted through ahead of the o2 sensor, my MPG went to sh*t. get the leak fixed, O2 sensor replaced, should go back up to 320 Miles per tank.

 

yes, that'll do it.

part of the problem is that your manifolds are letting air IN to the exhaust.. exhaust gases are going out of the leaky spot, but air is also getting in.

this throws off your O2 sensor, and causes nasty problems like this.

you need to get that fixed, and probably replace your O2 sensor and the problem should fix itself.

 

Thanks for the input. I replaced the 02 sensor two months ago. My other question: is it possible to replace the broken rear manifold stud(s) without removing the cylnder head and timing belt, etc... I did a search on this, but no luck.

 

If the fuel injectors are leaking, can a good flushing fix this, or should I replace them. The car has 92000 miles.

 

I seen posts (I forget where) from people who've said they've done it, so it must be possible.

 

it's possible, just not any fun. you need a right angle drill, as there's not much room under there.
remove the read engine mount and drop the engine down some, and the head will tilt down so you can get to it.

 

man, i only get about 250 mi/tank!!! something is definetly wrong with my max. i've been saying that to myself or so long and never checked it out! and i got a brand new o2 censor about two months ago when i got a new clutch/downpipe/etc....
I personally think its the the exhaust manifold...any ideas???