2001 Nissan Altima lurches when we accelerate

We bought a used 2001 Nissan Altima. It has 123,000 miles on it. It had a few minor issues, but recently it has started lurching when we go over 35 miles and hour and it will not accelerate. I am wondering if anyone has an idea of what the issue might be before we take it to a mechanic.

It is either a clogged cat or fuel pump. Cat would be my first thought. A back pressure test would confirm the cat.

Knfenimore suggests a solid possibility…Though a bit RARE but one that is rather easily proven out…just have someone rev the engine…and one person back at the tailpipe. When the engine is revved the tailpipe should be breathing out a steady or free flowing stream of exhaust… You WILL notice a free flowing exhaust… There will be a SEVERE discrepancy in the amount of exhaust gas movement and how fast the engine is turning if there was a problem. If there was a clog…the exhaust gasses exiting the tail pipe will be slowed severely…or almost like it was on a Delay…EZ to figure this out. A clogged cat does happen…but not that often…and is usually preceeded by noises and or some kind of event or the wrong fuel used…which is kinda hard to do also. Methinks personally its the MAF

My FIRST GUESS was your MAF Sensor…VERY COMMON Failure with the precise symptom you have. To test it…start the car and see how it is running…if it is doing the same thing…Open the hood and UNPLUG the MAF sensor …see if the condition changes… It will either STALL OUT Immediately…or it will run exactly as it runs now! IF it runs the SAME WAY…you just found the culprit!!! The MAF is located right near your Airbox…usually it is in the first segment of filter Hose that leaves the air box…but it WILL be somewhere in the Intake Stream of Air entering the engine. If you cannot locate it…go to Youtube and type in MAF location on your specific vehicle…or Google it…But my directions should lead you to it just fine.

You CAN remove the MAF and spray it clean with either Brake Cleaner or Strangely enuf…MAF Spray cleaner. Sometimes cleaning the MAF will take the vehicle from running how it does now…to running perfectly. Do NOT try to poke anything into the MAF Sensor… THink of the MAF as a lightbulb filament without the glass around the filament to protect it. So it can be rather fragile…you are trying to clean off the Filament with a spray of gum cutting solvent but you are NOT trying to touch said filament with ANYTHING. Go out and perform the MAF test that I outlined and let us know what happens. I would ALSO…LOOK AT YOUR AIR FILTER… Is it clogged or old? Remove the filter if you think it is suspect. The filter will look clean as you open your Air Box…this is because the Dirty side IS FACING DOWN and away from you…so you will be looking at the clean side. Do these checks and let us know…then we go from there.

It stinks not to have the car in front of us here…I personally can go thru about 10-15 different checks in a matter of minutes to see what does and doesnt work.