My ‘96 EB Bronco recently began having problems with hard start, rough idle, and stalling only on startup. It triggered the Check Engine light and codes P0171 and P0174. I read several BroncoZone tech posts that helped me track down the cause to a vacuum leak in a white (plastic?) vacuum line to the “blend door actuator”. A section of the white vacuum line outside the plastic loom in the engine compartment had deteriorated and had a hole in it.
I cut the factory black tape off the plastic loom, cut out about a foot of the bad vacuum line section and rerouted the remainder back to the door actuator. That immediately fixed the hard start, rough idle problem. I’ll replace the complete vacuum line soon. I still have to clear the 2 codes with my Maxiscan MS310 OBDII scanner as there may be another issue. I’d appreciate any advice on possible other causes for having both the P0171 and P0174 (lean - Bank 1&2) codes.
Here are before and after photos of the white vacuum line leak problem and the temporary fix.
![1720397698015.jpeg 1720397698015.jpeg](https://www.broncozone.com/data/attachments/27/27330-4d10c1657331823ff0e6d54e7efc2458.jpg)
![1720397639999.jpeg 1720397639999.jpeg](https://www.broncozone.com/data/attachments/27/27329-0d5354819a7a4632952663ac651afd34.jpg)
I cut the factory black tape off the plastic loom, cut out about a foot of the bad vacuum line section and rerouted the remainder back to the door actuator. That immediately fixed the hard start, rough idle problem. I’ll replace the complete vacuum line soon. I still have to clear the 2 codes with my Maxiscan MS310 OBDII scanner as there may be another issue. I’d appreciate any advice on possible other causes for having both the P0171 and P0174 (lean - Bank 1&2) codes.
Here are before and after photos of the white vacuum line leak problem and the temporary fix.
![1720397698015.jpeg 1720397698015.jpeg](https://www.broncozone.com/data/attachments/27/27330-4d10c1657331823ff0e6d54e7efc2458.jpg)
![1720397639999.jpeg 1720397639999.jpeg](https://www.broncozone.com/data/attachments/27/27329-0d5354819a7a4632952663ac651afd34.jpg)