P0134 code help

i have a 96 sunfire and recently had a new exhaust system put on my car and now my engine light is on. I scanned it with a OBD-II reader and it gave me the P0134 code. so i changed my O2 sensor and i dont have any frayed wires or anything but i keep getting the code?? can any one help

What kind of exhaust? If is one of those that increases the flow or just plain oversize, that is your problem.

The O sensor, the 2nd one does nothing for the PCM, but tells the PCM if the Catalytic Converter is bad. The problem is there is not enough hot exhaust to tell the O Sensor that is OK.

I read a post before about some guy that used Spark Plug Extensions. He screwed one on the sensor hole and the sensor on the other side. He said that worked.

By the way, why people calls it O2 sensor?

Just wondering...

Which O2 Sensor did you replace?

That code is for Bank 1 Sensor 1 (upstream).

i changed the O2 sensor that is right after the manifold... i change my entire exhaust system from after the manifold to the tail pipe and all i did was upsize a quarter inch and put a high flow cat on it and a high flow muffler

I bet if you put the OEM Exhaust back on, it will work just fine.

but i just put that exhaust on and its all welded on and stuff.. and i cant afford to put a new exhaust on again i just did it three months ago

Did you read my previous post?

Google on that.

GM Code P0134 Oxygen Sensor SLOW RESPONCE or INACTIVITY.

Oxygen sensors monitor the level of oxygen in the exhaust stream thereby permitting the Power Control Modual (PCM) or (Computer) to adjust the mixture ratio that is delivered into the cumbustion chamber.
Oxygen sensors only begin to operate when they reach a temperature of 349 C or 660 F and until this temperature is reached the PCM views this condition as oxygen sensor INACTIVITY. The PCM will not report this on a normal Start Up & Warm up & Run cycle as the PCM is programed to see this as normal. Now if you were to start and stop your engine prior to the sensors warming up and this was done a number of times witch was greater than the PCM's permitted programed number of times & cycles, a Code P0134 would be set and would remain in the set position until a number of normal cycles were detected by the PCM. Now if you replaced the oxygen sensor with a new one you have one of two choises re: the MIL (Check Engine Light). You either clear the DTC code from the PCM or operate the vehicle until the PCM's recongnized number of normal cycles are achieved at which time the Mil (Check Engine Lamp) will go off.
P.S. Many oxygen sensors have a heater element built in to reduce this warm-up time in order to give the PCM the data it requires to control fuel mixture (reduces required warm-up time). A failled heater element could be seen as a "Slow Responce" during the warm-up period.

I have the same exact problem on my 1999 Pontiac grand prix...its a 3.8 SE (non turbo)
I had P0134 and p0141 showing and i replaced both sensors with Bosch heated sensors...
We reset the codes and after driving for a few miles the service engine light came on again...but this time only p0134.

When you say the sensors have to warm up, when should this happen?

An 02 sensor should be up to temperature within 2 mins of driving at the most! I'd suspect either your Bosch 02's are not satisfying the pcm's heater requirements or the wiring is damaged etc.