allright i have a 2000 blazer 4x4 with the 4.3L vortec with a K&N CAI with 138,000 miles

all has been fine and dandy tell earlier this week. Monday it popped a SES light and went off monday night after work . haven't got it scanned yet so i don't know what tripped it, but this morning and afternoon when i went to lunch i noticed my truck didn't have any power. usually these 4.3L are pretty torquey and build a good amount of power down low. less than 2500rpm or so. well it doesn't have any "balz" tell about 3000rpm. it shifts fine through all 4 gears, but in 3rd gear when it reaches about 2500 rpm it will hesitate and drop to about 2000rpm then continue on about to 3000 then shift into 4th. it is not a shift point i know because i counted the shifts and the 4l60e don't have 5 gears the last time i checked .

it had spark plugs done about 10,000-15,000 miles ago with ac delco platinum. i did not change plug wires or cap/rotor however when i did them ( i should have)

my blazer does not get babied either. i pull trailers, flat beds , haul alot of tools. etc. So i know i am working it but the power loss is happening when i am not towing (have not tried it with towing yet, but i bet the loss would be more)

the part that scares me is the transmission went out at 70,000 miles and i'm getting close to 140,000 miles...

i ran some fuel injector cleaner through it this evening just for the heck of it. doesn't seem to be doing much.

it acts like it loses fuel so i think it could possibly be a fuel injector. the egr has never been cleaned as far as i know and i know that could possibly be another problem. my fuel economy as of tonight was 14.33mpg.

any suggestions or input is appreciated
thanks for reading all of this.

 

Did you recently oil your air filter? If so, you will need to clean you mass air flow sensor.

 

no i have not yet done that. my k&n is getting pretty dirty though. maybe it getting to restrictive

 

Clean the MAF sensor and see how that goes.

 

can i clean that out with carb cleaner or will that damage the sensor?

 

MAF Sensor Cleaning

Carb cleaner should work.

 

cleaned maf off . no change. threw some sea foam in it. still didn't change it. still need to do egr.

 

allright well i still haven't got around to doing the egr because of christmas with the parents , but i did do some digging on here and online and i found others that had a similar problem and it was 2 different things. one was the oxygen sensor ( i think there is 2 on these trucks correct?)

the other was the catalytic converter plugging up. which mines makes a very weird rattlling noise. is there a way to check to see if the cat is the problem before i go replacing parts that don't need to be replaced? i'm still trying to get my hands on a scanner hopefully monday. i heard of unplugging one oxygen sensor might do the trick but set a code. but if the cat was the problem i would regain my power by unplugging the oxygen sensor just for test purposes.

also on these trucks do they use a pre-cat and the cat? what would happen if the catalytic converter was removed and "burned" out? would it set any codes?

thanks for the input

 

well what you can try to see if it is the cat is to take the o2 sensor before the cat out completly. if you do this and you notice some gainn inn power than chances are the cat is clogged.

 

If your cat is rattling, then it is most likely the problem. Get it replaced and let us know how that worked.