Rachel Edwards

Asked by Jun 07, 2014 at 12:43 AM about the 2004 Audi A4 1.8T Quattro

Question type: Maintenance & Repair

Hey my name is Anthony and I just bought my wife a 04 Audi a4 Quattro 1.8t  and the
check engine light just came on with the codes p0300, p0420 , and p0299 can anyone
help me figure out what's wrong with this one said (the p0420) rich air/fuel ratio and other
said (the p0300)  lean air/fuel ratio. And today the esp. Light came on after I hooked the
battery  back up

4 Answers


I think i would start by changing plug,s and wires,if they have not recently been changed,usually this means not enuff fire to burn the fuel,so it throws you this code.Next check coil,s.


normally this only comes up when you have a spark plug issues or a plugged up air filter replace the plugs with only the top bosch plugs. also check the air flow filter and clean the air flow sensor. should help

Poly-Boi Masaniai

Hey where is air flow sensor


maf is that sensor body jsut after the filter box

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