I have a 2002 Blazer Xtreme with 118,000 miles. I have noticed rough idle recently then the other day I was on the freeway went to pass someone the transmission kicked down I started getting really bad knocking noise and no power I actually started losing speed. I then threw the P0101 (Mass Air Flow) I cleaned the mass air flow sensor and while I was at it cleaned all the intake tubing figured since I was in it this far cleaned up the throttle body as well. Replaced the K&N filter with a Fram filter thinking maybe the oil had fouled out the Mass Airflow. Still no cure I am no longer throwing the P0101 code but I am getting pining at 3,000 rpm and no power. I can no longer climb freeway grades at more than 65 mph. I tried to search this topic and got no results. Please help.

 

Sounds as though you are suffering from a failing catalytic converter.

 

oooh man ok so I was throwing P0100 I decided I am going to replace the mass air flow sensor. $100 dollars later and about 3 minutes work I jump in my truck jump on the freeway slam the throttle loud pinging at about 3,500 rpm now and loss of speed. Check engine light starts flashing at me I get pulled off plug my scanner into it NOW I am throwing a P0300 code. I have never had problems with this truck and now I am just looking for a stick of dynamite.

This would not be caused by a plugged CAT... would it?

oooh I forgot to include I just finished running a bottle (through several tanks not all at once) of lucas fuel injector cleaner through my truck and then I have all these problem onset.

 

A plugged catalytic converter can definitely cause the symptoms that you are experiencing, but have you checked the basics..?

When was the last time that a full tune up was performed (plugs, wires, cap, and rotor)?

You can remove the ICM (ignition control module) and coil to have them tested. If/when you do, have them tested at least 10 times in quick succession. This will heat them up simulating the operating conditions they endure on a running engine.

You can also test out the wiring to the MAF sensor. Since the original code you received was P0101 - Mass Air Flow System Performance, that thread will show you the trouble shooting steps as well as the wiring diagram. You will want to test continuity at the very least, but reading the wire resistance will tell you more. There should be very little resistance on the wire and it should not change if you move the wiring around.

 

(bows to swartlkk) ok so after the fiasco of trying to get home last night from work (a 30 minute drive turned into an hour and fifteen minute). Jump on the freeway thinking ok if I limp this thing home I will be fine get on the freeway ease on the gas up to 80 set cruise control by the time i got 20 miles into my 36 mile drive home i was down to 25 mph on the freeway. I decided to limp my truck to the mechanics and leave it there. He called me today the front catalytic converter on the truck's catalyst had disintegrated and sent chunks into the main catalytic converter thus plugging it. So..... after all said and done I am looking at about $900.

 

Glad you found the problem! Let us know how everything goes once you get it back!

 

Got the Blazer back today and it all seems fine. $900 dollars later its running really strong and I decided to break in the new Catalytic converts with a short 115 mph run across the freeway definitely smell the new welds but she is running great. Gonna take some getting used to the new exhaust note she is putting out now though.