A few months back my 2004 Xtype 3.0 engine light came on and the engine started chugging. it appeared to happen about the time when it wants to shift. So I went and had it scanned and it came up O2 sensors. so I replaced them (ugh) and the chugging still is happening and the Code that it is saying is still O2 ... What sensor or part is before the O2 sensor that may be erroring this out?


What questions or answers can I ask or provide so I can get this resolved and fixed as I want to sell the car but if I let people test drive this way I will have forever.

Thanks a MILLION

 

When you say "O2" code, some people mistake another code for an 02. what exactly was the code? Sounds like limp mode to me. Does it happen at about 2800 RPM?

 

Ok the Oxygen Sensors, the codes were P0171, P0174, I have replaced both Oxygen Sensors on the Manifolds (Sucked BTW) and I get the same code.

I guess I have not noted the RPM's but if it is in LIMP mode , Why if I have fixed the parts that are generating the Code

I am new to this Jaguar thing so I dont want to break things.

 

P0171 and P0174 are lean codes, 1 for each bank, not an O2 code. It can be caused by a bad O2 but is likely something else like:
Engine misfire
Air intake leak between MAF Sensor and throttle
Fuel filter / system restriction
Fuel injector restriction
Fuel pressure sensor failure (low fuel pressure)
Low fuel pump output
HO2 Sensor(s) (1/1, 1/2) harness wiring condition fault
Exhaust leak (before catalyst)
ECM receiving incorrect signal from one or more of the following components: ECT Sensor, MAF Sensor, IAT Sensor, IP Sensor, EFT Sensor, TP Sensor
It seems that most often it’s just a vacuum leak. Check your PCV hose first (a tube about 1 inch in diameter and 8 or so inches long running from the front valve cover to the intake.) Its right under the plastic shield over your engine. Inspect it for cracks, especially on the underside. If it’s good then move on to the brake booster line and IMT valves. The IMT o-rings are are notorious for leaking.

 

not sure if you got this fixed yet or not. I just got my car out of the dealership and those two codes were what showed up. It turned out to be a vaccum leak at the fuel pressure sensor.

Good luck.

 

I think I may have solved the issue. I replaced the IMT O-rings and so far so good. When I removed I did see where there was vacuum leaks happening and I hope this solves the issues because it was getting annoying.

Thanks to all for the advice