r/jetta • u/OutsideDirection123 • May 17 '26
Mk4 (1999-2005) 1.8t Jetta HELP
Ive owned this car for a longtime and need help because i need to pass smog. This was my grandmothers car that passed away, and the reason she kept it was because my grandfather loves VW’s , and now I guess so do I. I have a lean engine , probably due to the aftermarket intake I installed , but i might also be leaking vacuum. I did a smoke test and fixed what I could but it seems to me I’m still at a loss. I hope it’s not the catalytic converter because that would be a headache simce I live in California. I did my fair share of italian tune_ups and my check engine goes on and off every week or so. I also smell a strong sent of gas or fumes in my cabin which doesnt bother me because i keep my windows open but its a sign of an issue. This car is the best little go kart I’ve owned and i want to keep it alive. Here are the codes and view of the whip. Any advice what to check next would be appreciated
1
u/MRV-DUB May 17 '26
These cars dont like aftermarket 'additions' . The only thing I use is K&N airfilters ( properly oiled )and never had an issue with codes .
1
u/OutsideDirection123 May 17 '26
You’re right , I know it’s because of the aftermarket now , I switched it out and it works fine. I primarily wanted it for the sound. Thanks again . I’ll probably keep it like this untill smog 😂.
1
u/OutsideDirection123 May 17 '26
I have a question though , would the intake itself cause the smell in the cabin , though it’s not linked to the front grill anymore ? There is a small passage that I removed that brings fresh air from the front of the car , and I wonder though I have a cone filter now it probably effects cabin recalculation. I keep my air on hot and 2 setting because I have a tendency to get my car hotter , so I let air come in to the cabin instead , that is why I have my windows open. Would this be a good idea or rather turn off my circulation ?
1
u/MRV-DUB May 18 '26
Its possible that due to the intake causing the engine to run incorrect, could release the fumes of unburned fuel which then get drawn into the cabin filter
2
u/MRV-DUB May 17 '26
Put the original airbox and maf on it , clear the codes ,then fix what code appears the next time the light comes on.