SES Light and Possible Miss

[davbell22602]

1997 Chevy truck K1500 5.7mfi spiders

SES light came on yesterday and was ready to sell the truck. Truck is still missing but only noticable at full running temperature not a cold engine.

Scantool show P0420A - Low efficency cat

Cleared code

Checked spark plugs none were fouled or signs of running too rich, normal.

Compression Test

#1 - 200 then dropped to 195 within 2-3 seconds
#3 - 200 then dropped to 195 within 2-3 seconds
#5 - 200 then dropped to 195 within 2-3 seconds
#7 - 195 no bleed off
#2 - 195 no bleed off
#4 - 200 then dropped to 195 within 5 seconds
#6 - 195 no bleed off
#8 - 195 then dropped to 190 within 2-3 seconds

Put it all back together and had running sprayed it down with carb cleaner to check for vaccum leaks and got nothing. The whole 20 plus minutes no mis yet and the SES light hasnt came back on yet.

Drive it home with no signs of the SES light coming back on either.

Gonna do a engine top clean tomorrow with BG product. Also found a oil on it today moving it back out to the parking also. Checking that tomorrow also.

 

[oneluckypops]

dave unless you were using a leak down test your "bleed off' your reporting was most likely the tester itself leaking down.

 

[davbell22602]

dave unless you were using a leak down test your "bleed off' your reporting was most likely the tester itself leaking down.

I was just using a compression tester.

 

[bucket]

What's the compression ratio on the Vortecs? That's some high pressure.

 

[oneluckypops]

What's the compression ratio on the Vortecs? That's some high pressure.

I am thinking its 10:1
cant remember for sure though.

the motor itself is defintly not JUNK with that compression.

 

[crazy4offroad]

I am thinking its 10:1
cant remember for sure though.

the motor itself is defintly not JUNK with that compression.

SHHHHHHHH!!!!!!!


I think it's junked Dave, I'll give you $100 for the heads...

 

[oneluckypops]

SHHHHHHHH!!!!!!!


I think it's junked Dave, I'll give you $100 for the heads...

hell get the whole motor and do a swap.

 

[89Suburban]

Maybe you had a loose plug Dave?

 

[davbell22602]

Running better on idle since doing the BG induction top engine clean.

 

[davbell22602]

Changed oil and checked to see where the oil is leaking at but no results. Oil was all over the trany dust cover, starter, oil filter adapter and was wet on the rear of the oil pan. Checked oil sending and was dry as bone. Was told there known to leak. Going to AZ to put dye in it.

 

[Old77]

Scantool show P0420A - Low efficency cat

FYI...This code points to an issue with either you catalytic converter or an 02 sensor

 

[davbell22602]

FYI...This code points to an issue with either you catalytic converter or an 02 sensor

Hasnt came back on since clearing the code with a scantool.

 

[Jims86]

i am thinking its 10:1
cant remember for sure though.

The motor itself is defintly not junk with that compression.

9.1:1

 

[oneluckypops]

9.1:1

DOAH I was a wee bit off

 

[Old77]

Only by .9 OLP