car runs like crap

[tg580]

Just bought a 99 convertible Trans Am. It spits and sputters after 4500 rpm in first. I ran it with a Gtech and it wouldnt break into the 14's. Where should I start?

[Redphoenix1998]

unless you have done it, do a full tune, plugs, wires, fuel filter, air filter. Fuel filter is important, a lot of people forget to change that thing

[Mr. Luos]

I agree about the fuel filter.

Also, I disagree with any times the 'g-tech' spits out. Take it to a real track and see how it does.

[tg580]

Well, I took it to the dealer and he says that the catalytic converters are bad. He wanted $1500 to replace them. Luckily I know someone who owns a shop and he is replacing them along with putting a magnaflow muffler with crome tips on it for $500.

[OSU Football Fan]

Well, I took it to the dealer and he says that the catalytic converters are bad. He wanted $1500 to replace them. Luckily I know someone who owns a shop and he is replacing them along with putting a magnaflow muffler with crome tips on it for $500.

You could just forget the cat converters & go with a long tube set up.

[tg580]

Well, the new cats didn't work. They helped a little bit. It ran 14.80's on the Gtech. What else should I try?

[slims00ls1z28]

How many miles? Probably as suggested a full tune up though. Then try cleaning out the MAF.

[N20LT4]

Well, the new cats didn't work. They helped a little bit. It ran 14.80's on the Gtech. What else should I try?

Have you performed a tune-up on it yet?

[tg580]

The car has 71000 on it. You'll have to forgive me for my ignorance here. I really dont know a whole bunch about cars. What is a MAF and how do you clean it? Also, What all should I do for the tune up?

[hutch1999]

Have you performed a tune-up on it yet?

+1 sounds like some basic tune up work would help out

[Cutlass]

I agree. Get the car caught up on maintenance as described above.
The MAF is the Mass Air Flow sensor. It is located between the airfilter and the throttle body. Looks like this:

If your car is using a K&N type air filter and it is over oiled, the oil can get sucked into the MAF and contaminate the sensor and skew its readings. Basically the computer thinks there is less air flowing into the engine then there really is and the computer doesn't add the correct amount of fuel and the engine runs lean and crappy. Do a search on how to clean it.

[Speedy_Gonzales]

Well, I took it to the dealer and he says that the catalytic converters are bad. He wanted $1500 to replace them. Luckily I know someone who owns a shop and he is replacing them along with putting a magnaflow muffler with crome tips on it for $500.

buy some CRC MAF cleaner

[tg580]

so I should pull the MAF and just spray it down with the cleaner?

[Wesman]

so I should pull the MAF and just spray it down with the cleaner?

Correct. Let it dry for a minute, reinstall it, and then plug the harness back in.

[tg580]

do you think that a dirty one could actually make the car run about a second slower than it should?

[tg580]

What about a Hypertech power programmer?

[Wesman]

do you think that a dirty one could actually make the car run about a second slower than it should?

In a one word answer, yes.

The MAF tells the computer the volume of air that is coming into the engine. If the MAF reports that less air is coming in than what actually is entering the engine, it will run lean, sputter, and just plain run like crap. Easily resulting in your full second of 1/4 mile time lost.

[tg580]

its not really sputtering. I tjust seems like that it is not pulling real hard and revving that fast

[niterunnr]

do the tune up ALL 8 plugs and wires and dont forget the fuel filter... it could be clogging and starving for fuel that will cost u about 120 bucks for all of it and check the air filter also dont know how much that is but it shouldnt be much since u can get a k & n for about 50 bucks

[Speedy_Gonzales]

so I should pull the MAF and just spray it down with the cleaner?

spray the needle DO NOT TOUCH IT.......spray and clean up the thottle body and spray 3 seconds into intake (you can buy thottle body cleaner if you like or use MAF cleaner for both)

do you think that a dirty one could actually make the car run about a second slower than it should?

my car with a dirty MAF was running only 7 lbs of air. Clean it should run around 22 lbs...cleaning mine made a huge difference

What about a Hypertech power programmer?

waste of money

^^^^ Not true. Its 2000 to 2002 only on that extended warrenty
He appears to have a 1999

I stand correctd will edit post