vehicle runs very rich can smell fuel while running,burns through fuel quickly, idles low when warm, and seems to have no pick up and go tends to drop speed while driving up hill or on long trips. any help would be great! also cats are hollow and the cel comes on once and a while for o2 sensors but recently replaced both o2 sensors.

 

How many miles on your truck, why did you gut the cats, they need to be replaced. When did you last tune the truck along with 8 mm silicone plug wires, what are the fault code numbers you are getting and what octane gas are you burning?

 

180,000 plus, one cat was gutted when i bought it the other one was broke inside sounded like a real bad rod knock. tuned about five months ago with all dealer parts getting ready to replace fuel filter again. i change the fuel filter in all my cars after six months. fault code i believe was a 1187. unfortunately 87 octane.
does the brand wires and plugs really matter with these trucks? the dealer told me it will not run right with after market wires.

 

Dealer un-informed. 8mm good quality silicone wires last much longer, provide a better spark. About any plug can be used, from cheap Champion coppers to the more advanced plugs, just change often with the cheap ones. Better performance with the more advanced plugs for some users.

1187 is O2 sensor upstream heater circuit open. (Might be unplugged). In the old days, the carb decided how much gas. With electronic fuel injection, the ECU decides, either from a standard in memory (open loop) or from inputs from sensors (closed loop). Under closed loop the ECU is trying to maintain a 14.7:1 air to fuel ratio, no matter what position, various speeds, and various engine loads. The O2s are a big part of this "control loop" and when they are out of specification, the ECU will push the timing and fuel metering too far to one side to compensate, and you can run rich.

Will do better with premium. But until repaired, you'll be often thinking of this pix.

 

o2 sensors were replaced about a year ago, 1187 code only shows up maybe once in a while cel comes on then shuts off. just stumped at this point and do not want to keep throwing money at it, but moving cross country and need the truck to make it from the west coast to east coast.

 

wiring or dirty connector?

 

that was my next move. i am going to clean the harness at the ecu then all temp. sensors and see where that puts me. i also have a set of universal accel wires i might put on it.

 

Just curious..didn't look in the RAVE...

FI systems are regulated by the fuel regulator, which works off of vacuum pressure. If the vacuum line is disengaged or has a crack, it would run rich.

Does this occur? I've seen this issue with other vehicles....haven't come across this issue on LR's..

 

Running way to rich can be caused by many things, the cats and rear O2's have nothing to do with engine fueling.
If the front O2's are dead, if the coolant temp sensor is bad, if the plug wires are bad or the spark plugs.
Since you are running the wrong grade of fuel if your knock sensors are bad or lazy they too can cause rich run problems because they will not retard the timing to compensate for the wrong grade of fuel that is being used.
Hook up a live data OBDII scanner and watch the O2's and the engine temp.
Also a clogged air filter will cause this.

 

Everyone has a great memory. The rear O2s are NAS item so ECU can calculate cats are still present.

From the RAVE on the front O2 -


using signals from the remaining ECM inputs.


and on fuel pressure regulator:

Failure will result in a rich mixture at idle but
normal at full load, or a rich mixture resulting in engine
flooding, or a weak mixture. Although the fault will not
illuminate the MIL, faults caused by the failure may be indicated.

That six in vac hose to FPR - just toss and get a fresh piece of rubber. Everybody needs a couple of feet of rubber hose in their spares box anyway.