Hello

I am newbie on this forum, so please be tollerant for me and my English I hope you will understand me.

I have Opel Frontera 3.2 V6 with Liquefied Petroleum Gas installation (same engine as Rodeo 3.2 V6) and i have a little problem with this car. Engine a little bit Shaking on Idle (on petrol and on LPG too);( I checked ignition coils, spark plugs and lambda (all are O.K.), and OBD trouble codes (with ELM327 interface). On OBD i have the following codes: randomly P0171, or P0174. What i should check now? Maybe catalyst?
ps. Mileage of this car is ca 290000km (180197 miles) on petrol, and 10000km (6213 miles) on LPG.

 

Check your IACV and clean your TBI with spray cleaner to remove carbon you can try this on your IACV also.