Burnin rich update
#11
on the way home from work, car sounded way quieter than normal with loss of power, motor runs fine but it feels like im pulling another car, think this has to do with the gas consumption?? i then disconnected the MAF and drove, no check light, and the car ran the same
#14
how would i know which one is it? or would it be equally bad? also, would this be a one to one swap out?? im not a welder nor a blacksmith
Magnaflow 23477 Direct Fit Catalytic Converter - eBay (item 310306111318 end time Apr-21-11 06:30:08 PDT)
Magnaflow 23477 Direct Fit Catalytic Converter - eBay (item 310306111318 end time Apr-21-11 06:30:08 PDT)
#16
Join Date: Nov 2007
Location: Eastern PA,
Posts: 10,462
To test you want to pull the fuel pump fuse and remove an O2 sensor. Then install a a pressure gage.
youtube is your friend
YouTube - exhaust back pressure testing
You do not have to make an adapter like they show. Most Vacuum gages have a large cone that work fine for a crank test. You do not need to start the car for the crank test, that is why I said pull the fuse. If your cat is real bad it will not pass the crank test. Anything over 1 PSI is a fail. At around 3-4 PSI the car will not even start. 90% car that I have tested, if they pasted the cold crank test they will pass the running test.
Just make sure it is a Vacuum/pressure gage and not just a Vacuum.
youtube is your friend
YouTube - exhaust back pressure testing
You do not have to make an adapter like they show. Most Vacuum gages have a large cone that work fine for a crank test. You do not need to start the car for the crank test, that is why I said pull the fuse. If your cat is real bad it will not pass the crank test. Anything over 1 PSI is a fail. At around 3-4 PSI the car will not even start. 90% car that I have tested, if they pasted the cold crank test they will pass the running test.
Just make sure it is a Vacuum/pressure gage and not just a Vacuum.
Last edited by Gorn; 03-29-2011 at 08:18 PM.
#18
haha yea thats always an option
thanx 4 the test tip gorn
update- bout to test back pressure had to move the car, when i started it ran for a second then cut off, then started again and gave it some gas and it started to stammer and hearing some loud back fire arc, so i cut it off
thanx 4 the test tip gorn
update- bout to test back pressure had to move the car, when i started it ran for a second then cut off, then started again and gave it some gas and it started to stammer and hearing some loud back fire arc, so i cut it off
#19
Join Date: Nov 2007
Location: Eastern PA,
Posts: 10,462
Just a word of warning: as these higher power V8s will no longer run the clogging become a complete clog very quickly. I had a L98 with a no start condition and it had fuel and spark. I hooked up my gage like normal and spun the motor over. The gage blew apart in my hand and left my hand numb for a few minutes. These motors are just big air compressors if the exhaust cannot breathe. It very rare for that much back pressure but possible.
#20
thanks for not telling me that before i went under there else i woulda call my friend over to "help"
update- i pulled the o2`s before the cat to test, at idle the needle jumps between 0-1 psi, at constant 2000 rpm the needle jumps between 1-2 psi,
after running for for about less than a minute when i revved all the stammering and backfiring went away, gunna test one thing before i drop the car down, i`ll plug in the o2 back and run the car to see if the cats turn red.
update- i pulled the o2`s before the cat to test, at idle the needle jumps between 0-1 psi, at constant 2000 rpm the needle jumps between 1-2 psi,
after running for for about less than a minute when i revved all the stammering and backfiring went away, gunna test one thing before i drop the car down, i`ll plug in the o2 back and run the car to see if the cats turn red.