my 2003 Disco ii HSE 131400 k miles has me stumped
the idle is rough with a P0130 code
02 circuit (bank 1, sensor1)
so I did the following;
new MAF
new air filter
new fuel purge
new IACV
new plugs Bosch
new wires
new PVC
fuel treatment with injector cleaner
cleaned the air intake
new Bosch O2 sensors (all 4)
did throttle body heater bypass (it was leaking)

rough below 500rpm when in gear
when in park the idle is around 8rpm
the P0130 code is random.
after I clear it, i can go anywhere from
5 to 60 minutes
5 to 40 miles
cold to hot engine
before the SES comes on
Any ideas before I bring it the shop and pay for a diagnosis?

Thanks

 

Swap things left and right and see if the code moves. - coils, plugs, wires, injectors, sensors. Do one at a time.

 

Was this happening before you changed all that stuff?

If this is new after changing those parts, start here:
Check that it's plugged in firmly and seated all the way.
Check for a good connection to the O2 sensor. Look inside the connector and make sure that the contacts aren't bent or corroded which could cause an intermittent disconnection and error.
Check that the O2 sensor wires aren't cracked or rubbed somewhere, or maybe a rodent got to it.
With the engine running, use a scan tool to see the live values of the O2 sensors and compare the bank 1, sensor 1 readings to bank 2, sensor 1. Are they similar? Rev the engine a little and look at the voltage range and compare that with the other side. Is voltage changing about the same amount?
Swap the bank 1 O2 sensors left to right and see if you get the same code from bank 1, or if you now get the code on bank 2 instead of bank 1.
Did you touch the O2 sensor tip or get any junk on it when installing? If so, that can ruin them.

If this code appeared before your changed all that stuff out, check these items too:
Check for an exhaust leak on bank 1. You could have a small leak in the manifold or a gasket.
Check for an intake leak on that side by spraying carb cleaner around the intake base while idling. If the engine revs a little, there's a leak.
Check the condition of your fuel injector o-rings.

 

It's the o2 sensor plugs. There is coolant/cheese/water in them.

 

thanks for the replies and advice
been away and it took me a while to get back to the Rover
cleared the codes
then instead of th P0130 code I got a P0171

Changed out both left and right upstream O2s
I had already done this but figured maybe the new ones were bad
Anyway, so far so good - no codes
go figure

 

what brand were the old and the new 02s?

 

I've found compatible Rover parts from "trusted sellers" to be a complete crap shoot when I was changing out the Coolant Temp Sensor while I had the intake off.. That was a huge headache to track down what was going on.