2002 Jetta 1.8T engine codes-p0171,p301,p303 stuff idle
new plugs, wiring, MAF,coils
The p0171 is usually caused by a vacuum leak or fuel pressure problem.It can lso cause the misfire codes.There are also issues with the coils failing on these cars .You can swap coils for 1 and 3 cylinders to 2 and 4 and see if the codes goes to 2 and 4 cylinder misfires if so those coils are bad.
Fuel pressure regulator and residual pressure
Fuel Pump (FP)
Secondary Air Injection (AIR) system
do you think it could be throttle body, ruff idle
No that will not cause a rough idle it will usually cause a stalling issue or fluctuating idle.What I stated is what will usually cause these issues and is what you should check first .Unless it jumped times these need to be checked first.Hoped this helped.Positive feedback and bonuses greatly appreciated.
I click on the answers that you think we help fix this car and it won't let me in that page. It want a login and password, is that more money???
No it's not supposed to let you in these ate the issues that it can be .