my 99 chevy malibu sounds like an exhaust leak only while accelerating… not idling…

i just replaced the catylitic converter and the muffler, and this hasn’t solved the problem, also i have a major loss of compression and power… any help appreciated

I understand how you could say you have a major loss of power,but how do you know you have a loss of compression?

I don’t know where to begin with this. There’s no where near enough information to posit any kind of a guess.

Let me suggest you have it looked at by a reputable shop. Problems should be diagnosed before parts get changed.

i don’t know that it’s a loss of compression… and i’ve had a few reputeable shops look at the car and no one seems to think that theres any loss of power or acceleration happening, only i know because i’ve driven the car for 100,000 miles… i did also just have a full tune-up done, the mechanic said i went from a double platinum plug to a single platinum, and a no name set of wires… could this cause a loss in power?, and the catylitic converter was an aftermarket one, could this be causing it. i’m lost here.
please help…

Loss of performance could be low fuel flow. Has the fuel filter ever been changed? Air filter? Measure the fuel pressure with the engine under load (gauge installed, 40 mph, foot on the brake and gas).

the fuel pressure hasn’t been checked, but the fuel filter and air filter are new… i also had the fuel injectors cleaned at a local valvoline oil change place, and while i had my foot on the gas at 15 rpms to help clean out the injectors the catylitic converter turned red and was smoking badly…

If the loss of power came up after messing with non OEM plugs and wires, therein lies (at least part of) the problem. WHOOPS!

I see you said a mechanic said you made (wrong?) changes. Did HE replace the plugs and wires with the correct ones?

I would change everything back to the original required equipment.

Someone with more knowledge can comment on the aftermarket converter.

It may be a good idea to have a compression test performed.

Just curious: How were you convinced to go for the injector cleaning? And how much did you pay?. Cant believe that getting the converter so hot it turned red was good for it,was this the new converter?

yes this was the new converter, , i paid 59.00 for the cleaning, and thought of it as a last ditch effort to correct a problem that seems to be invisible to mechanics that i bring the car to… i feel that they all believe that it’s only a malibu and it shouldn’t have any more power or pickup then it has now… i know it’s not a porsche, but it’s running more like a 1970 beatle…

no he didn’t replace the plugs and wires with the correct ones… and he didn’t actually say they were the wrong ones… he only made it sound like i had a better set of plugs and wires on before… these that i just put on were champion single platinums… i had ac delco double platinums on before, and ac delco wires… these wires were a no name brand… this all came from strauss auto store, and i asked them for the best plugs and wires for my car… the champions and the no name wires were what they sold me…
as im driving it more i swear it has some kind of exhaust leak, even though 3 different mechanics from meinekee, and from aamco, and a private mechanic all said they don’t hear anything that would make them believe theres an exhaust leak… it sounds just like it did before i had my muffler replaced due to an exhaust leak… could the muffler maybe be bad that meinekee sold me?

Its been my experience that a loss of power that cant be traced to a fuel or ignition or engine mechanical defect end up being in the exaust system,plugged engine cant breath. I have to say another mechanic must look it over. I have driven the 99 malibuV-6 good power and quiet,so I agree something still is not right,your mechanics are missing something

i think i’m going to try midas muffler… they usually are pretty thorough, expensive but thorough…
i’ll let you know what they come up with.