pontiacdog

I bought an '99 trans am 3 months ago and since the beginning it has had a weird problem.. The previous owner said it was caused by old gasoline, which clearly wasn't the case.

Every time I accelerate, at about 2200rpm, the car stops accelerating for a moment and then continues. This "lagging" happens on every gear and feels very sharp, it's like the car kicks back.
I've had spark plugs and their cords replaced.

Diagnostics say two oxygen sensors are faulty but I've had them replaced - twice. They also have a tendency to come loose by time which I think might be part of this problem.

Following codes usually appear:
P0137 & P0157
P1416
P0004

I live in Finland and unfortunately there aren't many shops here that can help me with my car.

pontiacdog

I heard AIR check valves can do this sort of problems.

Changed them two days ago but with no significant improvement.

Could it be the catalysators..?

got milk??

iTrader: (18)

Disconnect your MAF, drive it around and report back. Disregard the SES light for the MAF. This test will help narrow your problem down. Your car is going to disregard your front 02 sensors and the CATS all togther and run in Speed density mode. Please post up your results.

RedHot99T/A

i had a similar problem,my fuel pump was failing wasnt feeding full pressure so if possible check your fuel pressure also.

white99ta!!

check your fuel pressure. it couldnt hurt to replace the fuel filter.

Kuhny

Start with fuel filter i had one same symptoms and it fixed it good luck!!!!

Paul Bell

iTrader: (9)

Welcome to LS1tech! SEARCH will be your best friend.

Does your MAF still have the screen in it like this one?

pontiacdog

I replaced the catalytic converters and fuel filter.. only to find out the car throws in new fault codes and the hesitation during accelerating persists.
This time the fault codes are:

-Secondary Air Injection System Malfunction
-Knock Sensor 1 Circuit Low Input (Bank 2)
-Mass Air Flow (MAF) Circuit Malfunction

MAF is easily replaced.. however the knock sensor one disturbs me. Does this mean I have to replace the engine?

Paul Bell

iTrader: (9)

WOHA, slow down!

This means you need to find a friend or shop that can help you troubleshoot your problems and get you fixed up again.