I've searched around for similar problems but I couldn't find much

basically I just had my intake manifold gasket replaced a couple days ago, and when I got the car back it has a couple noticeable symptoms:

-Bad acceleration, unresponsive when I push down on the gas
-Bad Gas Milage
-Running hard when idleing
-After long drives I can smell gas (from the rear of the car, maybe the exhaust)

The car was running a little rough before I took it in to the mechanic, but the problem greatly magnified just recently

A while back I had similar symptoms, yet they weren't as noticeable, and it turned out to be that some of my fuel injectors were bad... I only had a couple replaced so I'm thinking the older ones can be causing the problem?

What about 02 sensor?
thanks

 

replacing the o2 sensor will give u better fuel economy

 

it could be ur maf sensor too i think, i dont know which ur car has but if it went bad it will usually just dump fuel in, or at least it did on my old bmw lol.

 

You may have a vacuum leak around your intake manifold. I used starting fluid to hunt down my vacuum leak. Spray a section of the manifold and listen if your RPM changes. If you notice the rpm change then you know you have a vacuum leak. Replace your fuel filter and make sure you TV cable is adjusted correctly. A misadjusted TV cable can kill your tranny.

 

Exact same symptoms I had, especially the smell of gas and bad mileage. Vacuum leak I would say. Trace EVERY one of your vacuum lines (small, about 3/16" in diameter, black, rubber material, soft. Look for splits, holes lines that are not attached (this is actually what I suspect, seems as if your mechanic did the job and didn't reconnect everything properly.) Just check and make sure ALL of your lines connect. Here is a simple diagram for what to look for in terms of line location: Vacuum Diagram

When you are finished, run some Seafoam fuel treatment into your gas tank. If it is a vacuum line, then you are running very rich with the symptoms provided. This will cause carbon build ups and all kinds of crap that will clog up your system, making it inefficient. I noticed a 3mpg boost OVER what I GAINED back from fixing the broken vacuum line after using a can of seafoam (under similar driving conditions). I went from about 10 to 17 to 20ish.

Good luck
_Clark

 

Check the catalytic converter (mine was plugged), I had similar problems with my car and spent a **** lot of money to fix it, eventually I took it to a dealer and spent more money to have it re-checked just to find out that it was the cat.

 

Allright I'm gonna check it out in the next couple days...

I forgot to mention that it has also been taking a while to start.. i dunno if that's significant or not.. Hopefully I'll get this thing nailed

 

Yeap, sounds about right. When I took mine to the dealer it sounded like I had a really hot cam, it died on me and wouldn't start after that, we had to push it to the bay. The cat was full of rust and it weighed a "ton".
All my starts used to take a while. Check it out before you spend any money on it and if it is the cat then just buy a hi flow one for less than $100 don't get it from the dealer, they charged me about $2000 Canadian for the cat, fuel pump and labor. Before I went to the dealer I had gone to my NOW ex-mechanic, he charge me about the same, never fixed the problem and because my car died at the dealer I couldn't go anywhere else so I had to get it fixed at the dealer. The mechanic changed the wires, plugs and coil so I guess the engine run a little better when I picked the car up and because of that it had enough "muscle" to push the burned gas through the cat but once the rust built up a little again the car started acting up, hard starts, hesitation, poor idle, no power, poor mileage, etc.
Let us know what the problem is with yours when you find out.

 

O2 sensor wouldn't make it hard to start.

Bad fuel pump could cause all of these problems. Check the fuel pressure before you go changing any parts.

 

Allright I'm gonna have it looked at this saturday, I'll let you all know what the prob is. *fingers crossed for something small*

 

I missed the part about the intake gaskets being replaced the first time I read it. Since it got much worse after that, the things that were disturbed in the process should be the first things checked. Fuel pressure #2 (could be a plugged fuel filter).

You didn't mention any SES light. Is it staying or coming on after it's running?

 

Nope, the light hasn't came on at all

 

Who changed the intake manifold gasket?

 

A mechanic who is a friend of the family. He use to work for a GM dealership doing repairs, but now he just does repairs on the side. Anyway, I think hes pretty trust worthy, but doesn't mean he couldn't have made a mistake.

 

Alright!
It was the ...timing belt..

My mechanic got lazy when putting everything back together after the intake gasket job. The timing was way off, and this caused the great increase in power loss and the hard idle. Because of the power loss, i also had the crappy fuel economy. So fortunately he fixed it for free.

As for the gas smell... It must be something else, but overall the cars running great right now and doesn't crank long when starting like before...

So good news is that it was something small, and didn't cost much
Bad news is that i don't trust my mechanic anymore