tiburon354

Ok. So about a month ago I noticed my car was lacking in power and it was also sputtering a bit. It seemed if the engine was cold it performed way worse to when it was warmed up, although when warm still didnt perform as good as it should.

I ran codes and found the secondary o2 sensor is no good and hasnt been since i owned the car and p1128- fuel system lean- part load.

I took it in to my mechanic and weve done the following things- changed spark plugs as they were pretty fouled up, new tps and new fuel pump.

The car sometimes will turn over, but as soon as you hit the gas peddle, it dies. Sometimes you cant even get the car to turn over now.

My mechanic cleared all the codes on the car. the only thing coming upo is the secondary o2 sensor, which I dont believe is my problem.

Ive done a search and it seems like it could be the primary o2 sensor or the maf sensor, which i have already cleaned.

Has anybody else had this problem or can give some advise?

Mods are obx header, catco high flow cat and motoria exhaust..

ONLY1DB

did you swap out your fuel filter? you can back probe the MAF to see if your getting the correct voltage. the voltage will go up as the tps percentage goes up.

you could even have a leaking intake manifold gasket as well. no misfire codes?

tiburon354

Fuel fuel filter was checked, but wasnt changed. It was clean as a whistle.

The problem kinda got worse over a period of a couple weeks.

The mechanic has kinda gotten to the point where hes given up because he cant figure it out..sad..lol

REDZMAN

What was the last work you did on the car before this happened?

Sounds like it is probably more than just one problem, but it also sounds like you are having a breathing problem. First thing I'd do here is check your exhaust. it sounds like you have some blockage, possibly a destroyed cat that has broken up and blocked your exhaust outlet. When you hit the gas it is putting more pressure and then choking off.

Could explain the LEAN code for your secondary o2 sensor also.

Looking at a fuel filter isn't going to do much, if it's been 40K miles or so, change it. Run a quality fuel injector cleaner through your system, and check that cat! Hell, take the header to the exhaust apart, and see if there is anything rattling or blocking the gasses.

tiburon354

The last work that I had done to the car was installing the headers/exhaust, which was last summer. But I also had the fuel filler neck rebuilt last fall.

The fuel filter has about 6k on it. I usually run fuel injector cleaner through maybe once every couple months.

What would cause the cat to break apart so quickly. It was brand new when I put it on last summer?

i8acobra

Temporarily swap the MAF with a known good one.

REDZMAN

What kind of cat?

Cats can be fickle. Another member here was just running rich and melted his cat internals, making his car run like poop.

I've seen folks get in a decent accident when the cat is red hot and the honeycomb inside breaks apart and then gets blown back blocking the exhaust.

Start at the intake, move your way all the way back to the tailpipe, check every sensor to see if it is working right or getting the right readings. Check everything for leaks, cracks, and if it is blocked or not.

It would probably be best to get that CEL code and check the trouble shooting procedures in HMA service for it.

tiburon354

Update-

Well the mechanics gave up on the car. I bought a used MAF sensor from the junkyard but it seems the car is worse. Now the car doesnt want to start at all. Battery is fine as I charged it last night. The stereo plays and lights work. But as soon as I go to start it, nothing. No turning over, no clicking, absolutely nothing.

Does anyone have an idea of what I should look at next?

Stocker

Stereo might play and lights work, with a too-flat-to-start battery.

You should look at all the sensors, as was suggested previously. I may as well mention that my P1128 was caused by a faulty primary O2 sensor. Fueling problems will cause a cat. to go bad in a hurry, as suggested. A car in a good state of tune should almost never have a cat go bad.

edit: also try a different mechanic! These are *simple* cars. Someone who gives up so easily, you don't want touching your car for so much as an oil change.

REDZMAN

Wow, that Mechanic sucks. Follow the steps given to you, or folks won't help at all.