Help!!! Check engine codes p2181,p0171

[V-DUB DAN]

Ok so I have a 2003 VW Jetta GLS and these are the codes I have

P2181=Engine Coolant System Performance

P0171= Mass vacuum leak

Engine isn't overheating, thermostat needle is at halfway mark. Grabbed upper radiator hose opens when its supposed to so thermostat is operating. Recently changed CTS (coolant temp. sensor) not OEM, ran ok for ~80/90 miles then CEL turned on again. Have to get this fixed my car is 6months past due for registration b/c of this.

As far as the vacuum leak there are no clamps around the hose that plugs into the FPR (fuel pressure regulator) and the hoses that leave the "Y-vacuum pipe thingy next to the valve cover dont have clamps either, so i believe that would solve that but I need to know what else to check.

Please help I want to solve this @#$% A.S.A.P.

- V-DUB DAN

[Pssst...passed you]

P2181=Engine Coolant System Performance= from ross-tech:
Check Engine Coolant Temperature Sender (G62)

Check Coolant Thermostat
Check Engine Cooling System
Put the key on, fan speed on 1, and push the a/c switch. Are both fans kicking on? If not, you found the problem.
Put the key on and fan speed on 1 with temperature set to hot. Does heat come out readily from the vents?
No. Probably the water pump is gone.
Yes. Probably the thermostat is gone.


P0171= Mass vacuum leak= lean due to MAF being dirty/faulty or leak in vac system

is idle rough? stumbles? flashing CEL?

[V-DUB DAN]

No flashing CEL no engine performance issues at all really... gonna do the test you recommended. Do I wait for it to get to 190DEG or conduct upon startup?

- V-DUB DAN

[-vdub-]

I would imagine your do it with the car warm. Although you can test the fans with it cold but the other stuff it has to be warmed up to tell if heat is coming out of the vents or not

[V-DUB DAN]

Passed the tests, fans kicked on as required, about to change out thermostat, timing belt, CTS, thermostat housing, pullys, tensioners, etc this is gonna be a pain in my ass.

[Pssst...passed you]

If you used non Petosin coolant it could be a sensor in the globe as well....

[V-DUB DAN]

Never heard of that, will try that; do you know what its called or part number

by any chance?