How to fix a P042E fault code
A stuck EGR valve can be carbon, a failed motor or a wiring fault, and each one costs a different amount to put right. A £100 + VAT diagnostic where the vehicle is parked shows what P042E needs.
Fix options for P042E compared
| Fix | When it's the answer | Where it's done | Price |
|---|---|---|---|
| Mobile diagnostics | First, to command the valve and see whether it moves | Your home or workplace | £100 + VAT |
| New EGR valve | Carbon has jammed it or the motor has failed | Garage | Garage quote |
| Wiring or connector repair | The valve works but isn't being told to move properly | Garage | Garage quote |
| EGR delete (software) | Instead of a new valve | Where the vehicle is | £220 + VAT |
What P042E means
The official wording is EGR control stuck open. The ECU has commanded the EGR valve to close, and its position sensor shows it hasn't.
What causes P042E
- Carbon jamming the valve in the open position
- A failed valve motor or gears
- A faulty position sensor reporting the valve as open
- Wiring or connector problems at the valve
Symptoms you may notice
An EGR valve stuck open floods the intake with exhaust gas at idle, so rough running, stalling as you slow down and black smoke are typical. Power usually drops, and many vehicles go into limp mode.
Using the vehicle with P042E
Stalling at low speed is a real risk with a valve stuck open, so keep journeys short and careful until it's fixed. The extra soot also heads into the DPF, which can lead to a blockage if it's left for long.
What happens on a P042E visit
Know the price
A diagnostic visit is £100 + VAT.
Valve tests
We command the EGR valve open and closed and watch its position on live data.
Your answer
You'll know if it's carbon, the motor, the sensor or the wiring, and a garage replaces any part using our findings.
Delete option
The £220 + VAT EGR delete can be done on site. Rangers with the locked SID212 ECU are handled off site instead, for £1,200 + VAT and a 7-day turnaround.
Related code P042F
P042F is the opposite fault, EGR control stuck closed. The valve has been told to open and hasn't moved, which usually raises combustion temperatures and diesel knock instead of causing stalling. If your Ford Ranger is showing P042F, whether it's a 2.2 or a 3.2, it's tested and fixed the same way as P042E.
How much does it cost to fix P042E?
A wiring fix costs less than a new valve. Our EGR valve replacement cost guide covers the valve, and the diagnostic tells you which applies.
Is it worth fixing P042E on an older or high-mileage vehicle?
Yes, if it stays on the road. Stalling is a safety risk and the extra soot can block the DPF.
Will replacing the EGR valve always clear P042E?
Usually, if the valve itself has jammed. If the wiring or the ECU's signal is at fault, a new valve won't help, so test first.
Can you sort P042E at my home or workplace?
The diagnosis happens on site, as does the delete, while repairs go to a garage. A flow code such as P0402 may appear with it.
Do I need a diagnostic before you can quote for P042E?
Yes. Commanding the valve on live data is the only way to tell carbon from an electrical fault.
Is an EGR delete for P042E legal on a road vehicle?
No. An EGR delete is for off-road and export use only, and Is EGR delete legal? sets out the rules.
Book the right fix for P042E
Send us the registration, the code and whether it's P042E or P042F, and we'll confirm the price before booking.
More fault codes explained
Eccles, Manchester M30 0SF