- Dec 19, 2013
- Fort Worth, Texas
This subject comes up every now & then on here, So I thought I'd share..... 2006 Cadillac Escalde ESV LQ9/4L65E was brought in yesterday, Notes on the ticket stated....... *Complaint.....Low Power, Flashing CEL. *Both Catalyst inspected visually with a bore scope. *Plugs, Wires, Coils, O2 sensors, & MAF sensor replaced. *Previous shop has recommended a replacement engine. *Owner seeking second opinion. Scan revealed a P0300 (Random Misfire) & a P0101 (MAF Performance). Misfire monitor history confirmed misfires on cylinders 2,4,6,& 8. My instincts were saying clogged catalyst on Bank 2....But I took it on a test drive anyway. Low power, Heavy misfires on Bank 2, And the MAF Grams Per Second maxed out at 87.....Should be 140-160 on a V8 GMT800. Decided to 100% prove it out given the owner has spent quite a bit of money already & has nothing to show for it! Components needed..... Fuel pressure-Vacuum Combo gauge.....HERE 3/8" NPT, 90Â° 1/4" Barb fitting.....HERE 18mm Anti-Fouler.....HERE You will need to use sealant on the 3/8" NPT threads as it's a loose fit into a 18mm hole, I used Loctite 518 Flange sealant on mine. A longer hose than what comes with the Horrid Freight gauge would be a good idea. The Escalade had 10 psi of backpressure @ 2,000 RPM free-rev! Bank 2 catalyst DID visually look good on the Inlet side, The Outlet showed some telltale signs.......But no visible meltdown.