Hey guys, I'm new and hoping someone can shed some light on my Dads blazer problem.

the car
2002 Chevy blazer 2wd
4.3
147,000

My dad hasn't kept his car up to date. Well recently i was borrowing it decided to change the oil. The next day my girlfriend says i can use her corolla until my car is fixed so my dads blazer sat for about 30 days. When I went to start it, it back fired and broke the circle piece that connects to a the pcv valve by a rubber hose. Cel came on. I heard the air rushing into the engine so I jammed that piece back on and it idled fine. The next day or so I lost power and when I mean lost I barely was doing 50 on the freeway with the pedal all the way down.

The things I just recently did

Fuel spider (it was used, i know... but my dad just wants to get it running to sell)
changed spark plugs and wires
rotor and distributor cap
new pcv valve
new air filter
clean maf sensor with correct cleaner
changed one 02 sensor
Fuel filter

I took it to a shop and they said it was the spider and they suggested doing the spark plugs rotor cap and wires because they were original so thats what led me to do the work. I just finished test driving it and it is exactly the same, if not worse. it does idle a lot better and intially when i started it up it sounded smooth when I revved it but all most died when the rpms would drop

The fuel gauge doesn't work all the time so i know the sending unit is bad

I can only guess that the fuel pump is bad. but when i'm sitting still and I rev for the most part it doesn't hiccup. at least after all the work i've done. it didn't want to go past 3k before without sounding like a can of rocks coming from the engine.

i'm really hoping someone has had this exact problem and knows the solution or how to help me diagnose it

Thanks in advance

 

check for restrictions in the exhaust, cat converter.

 

Bet its the cat

 

And how do I do that? I've heard from buddies that you can use a vacuum gauge to determine if you have a clogged cat but don't know what numbers I'm supposed to have when I hook up the gauge. And where to hook the gauge to?

 

if you replaced a front O2 sensor, pull it out and drive it.(since that would possibly come out easily-if you didn't replace a front one, pull one.) If it is better then the smart money would be on the cat. Beyond that a fuel pressure test would be in line-good luck-Jerry

 

Also how much exhaust is coming out

 

I have a fuel pressure gauge and I attached it to the fuel rail and it read somewhere around 60 and 65 when I revved the engine if I remember right. I did it a few weeks back when I really thought the problem was a bad fuel pump

Yeah I definitely will try that. Do you think by unplugging that little opening will let enough exhaust out to tell if thats the problem? I mentioned that to a technician ( not that great of one in my opinion) and he said i need to remove the exhaust where the three bolts in the picture below. The strange thing is on the same technicians hand held device ( looked like a iPad type device) said bank 2 sensor 1 need to be replaced which we drove down to auto zone and bought the sensor. it didn't fix the problem but supposedly he got reading from that sensor.

When I took it to the shop they said I needed to replace bank 1 sensor 1. well if you look at this diagram thats the same sensor that we replaced. hence the reason why the technician buddy is not really good.

Right now I don't have any codes coming up on my little obd2 reader but I also haven't driven the car all that much since it won't accelerate.



I assume by putting your hand over the exhaust and revving the engine? thats what the technician buddy did while he was looking over the blazer

 

you can do it his way but I've pulled O2 sensors many, many times verifying the issue. It works well for me-and as recently as last week. Good luck. Jerry

 

Pulling the O2 sensors will decrease the backpressure enough to inform you if the cat is plugged or not. This will also set codes and turn the CEL on. Also with the O2 sensors removed, hot exhaust is going to be hitting areas that were not designed for this, so best to create some deflection shields and only run engine for a short time.

Also try this: with exhaust cold, use the side of your fist and hit the cat several times lightly and listen for a rattling sound. If so, then the internals have broken loose and time to replace the cats.

 

Just my 2 cents worth...I've hit with my fist many convertors that rattled and performed sufficiently-ie kicked no codes/no drive ability issues and most of my customers would live with that-that is if I'm not paying for a new convertor under a warranty situation (as in a recent vehicle purchase). I've also had many convertors that didn't rattle that kicked 420 codes and either did or didn't offer drive ability issues as well..and as far as pulling the O2 sensor..I wouldn't drive it cross country that way and most likely when you pull it-it should be cool-that is unless you want to burn your paws..and from a cold start, going a mile or so, I doubt there will be any need for deflectors. This is how I often do it..what anyone chooses to do is his or her choice. Just trying to help..Jerry