Removing and installing gas rail sensor G401: VW (CPGA, CPWA)
Step-by-step removing and installing gas rail sensor G401 for the VW (CPGA/CPWA): factory workshop text.
Workshop procedure for VW — the factory write-up, straight from real workshop data.
📋 Procedure
Removing and installing
gas rail sensor
G401
Special tools and workshop equipment required
Torque wrench
V.A.G 1331
Prerequisites for removal
DANGER
Risk of explosion and danger to life due to escaping natural gas. A hissing noise is a sign that there are leaks in the natural gas system. Leaks in natural gas system may lead to uncontrolled escape of natural gas.
Risk of explosion leading to serious injuries or death.
Do not perform any kind of work on the natural gas system if leaking gas can be heard.
If a gas leak can be heard (hissing), never drive the vehicle into the workshop.
Park the vehicle outside and cordon off the area.
Empty gas system
Rep. gr.
20
Fuel tank; Releasing pressure in high-pressure line
.
Pull off connector
1
and unscrew
gas rail sensor
G401
2
.
Installing
Install in reverse order.
Note
The natural gas system may not be put into operation until it has been tested.
The necessary scope of the leakage test depends on the pressure section which has been worked on.
Observe the following allocation!
DANGER
Risk of explosion and danger to life due to escaping natural gas. Leaks in natural gas system may lead to uncontrolled escape of natural gas. Risk of explosion leading to serious injuries or death.
Check natural gas system for leaks.
Allocation:
Chapter
“
Distinguishing between pressure sections of natural gas supply system
”
Open fuel tank shut-off valves
N361/N362
using
hand wheel
T50026
.
DANGER
Risk of explosion and danger to life due to escaping natural gas. A hissing noise is a sign that there are leaks in the natural gas system. Leaks in natural gas system may lead to uncontrolled escape of natural gas.
Risk of explosion leading to serious injuries or death.
Do not perform any kind of work on the natural gas system if leaking gas can be heard.
If a gas leak can be heard (hissing), never drive the vehicle into the workshop.
Park the vehicle outside and cordon off the area.
Check the gas system
Chapter
“
Checking gas system for leaks
”
.
Specified torques
Tightening gas rail sensor
Chapter
“
Assembly overview - gas rail
”
.
TorqFix answers live for your specific car — tell it the engine code and it serves the matching sequence, torque figures and wiring for that exact variant.
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Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com
The story behind TorqFix →Workshop data on this page last updated 20 Sep 2026.