[4th Gen : 01-07]: 07 T&C 3.8 Struggling at high RPMs
#1
07 T&C 3.8 Struggling at high RPMs
Our van doesn't get driven hard, so I'll start by saying I don't know how long it's been like this. It seems to get a little better when it's been running a while, but above 4500, it more or less hits a wall and barely accelerates. Might even start slowing down until I let way off and it finally shifts up.
Potentially relevant info:
Sometime this summer, it started having a harsh downshift when slowing to a stop or for a turn.
Thanksgiving-ish, it started throwing a P0420.
Replaced the plugs (NGK g-power), wires (OEM), O2 sensor (acdelco).
Code persists. I plan on putting in a O2 extender on the 2nd sensor.
It burns about a quart of oil every 2000 miles.
Is the cat plugging up, or what else could it be?
Potentially relevant info:
Sometime this summer, it started having a harsh downshift when slowing to a stop or for a turn.
Thanksgiving-ish, it started throwing a P0420.
Replaced the plugs (NGK g-power), wires (OEM), O2 sensor (acdelco).
Code persists. I plan on putting in a O2 extender on the 2nd sensor.
It burns about a quart of oil every 2000 miles.
Is the cat plugging up, or what else could it be?
#4
Start it up and hold a gloved hand over the tailpipe. Increased exhaust pressure leaking out a hole anywhere will increase the noise and make it easier to find a leak. Eventually the engine will die.
It does sound exhaust related but I'm thinking it's partially plugged and it's probably the cat that's the culprit. Just from reading more often than not that's the cause of a P0420. http://www.obd-codes.com/p0420
It does sound exhaust related but I'm thinking it's partially plugged and it's probably the cat that's the culprit. Just from reading more often than not that's the cause of a P0420. http://www.obd-codes.com/p0420
Last edited by Cougar41; 12-31-2013 at 04:56 PM.
#5
In the meantime, does anyone know the difference between Magnaflow's standard and OEM grade cats? Does one flow better than the other, or have higher quality pipe materials?
http://www.magnaflow.com/02catalytic...irectfit=93202
http://www.magnaflow.com/02catalytic...irectfit=49948
http://www.magnaflow.com/02catalytic...irectfit=93202
http://www.magnaflow.com/02catalytic...irectfit=49948
#6
I replaced the cat with Magnaflow's 49 state unit. The original had deposits forming on the face of the brick. The result is a remarkable increase in power. Mostly just restored power, I'm sure, with a small increase relative to stock given the high flow nature of Magnaflow's products. And the exhaust has some burble now. I'll try to get a pic of what was going on with the old one.
#7