Cadillac Catera and Cimarron Forum Discussion, 99 Catera p171, p174, p442 DTC Codes in Past Cadillac Vehicle Discussion; I have a 99 Catera which has been setting p171 and p174 codes for a while now. Just got done ...
I have a 99 Catera which has been setting p171 and p174 codes for a while now. Just got done with a timing belt change and now I am getting p171, p174, AND p442 codes. I have read previous posts about replacing the MAF sensor when both the p171 and p174 codes are set. I was just about to order the part when I checked today and the 3rd code appeared. Not sure if this is an additional clue which could point me to a different trouble which is now setting all 3 codes OR if I have an additional issue.
I have inspected the induction system thoroughly after the timing belt job...all looks good. I can't seem to find any posts on the p442 code which could point me to a common trouble spot with the EVAP system.
Any advise / guidance would be greatly appreciated as I don't want to plunk down $150 for a MAF sensor only to get all 3 codes re-appearing after I do so.
The p171 is a Fuel System Lean Bank 1. The P174 is Fuel System Lean Bank 2. The p442 is a Small Leak Detected in EVAP System.
Upon inspection of the EVAP purge valve, I found a green colored collar sliding up and down the hose which runs from the valve to the EVAP service port. I need to pull the plenum to further inspect but it does look like a potential cause for the EVAP leak.
FYI to all....I replaced the MAF sensor and it seems to have cleared the p171 and p174 codes...which makes sense since those were the Lean Codes for Banks 1 and 2. I really saw a difference immediatly after I replaced the sensor. The engine didn't race up above 2000 RPM on the first start of the day as I had become accustomed to. Additionally, it doesn't run roughly for the first few minutes after the first start of the day (especially on cooler mornings). As for the p442 code, I think it is a separate issue. It came back after I cleared the codes after the MAF replacement. As I mentioned earlier, I found a green collar sliding along the tubing which runs between the EVAP service port and the purge switch. Upon inspection, it looks as if it snaps behind the connector at the service port to ensure it stays fully seated. I put the collar back in place and I am continuing to drive my Catera to see if that keeps the p442 code from getting set.
Well....my final update for this post is a successful one...the p442 code I was getting was due to a bad gas cap. Upon a close inspection, I found that if I pulled directly out on the cap, it would pop out of the filler neck very easily. This was after hearing the 3 recommended "clicks" when tightening the cap. I replaced the cap (best price I found was at RockAuto...none of the local stores carried it and I didn't even check with the dealer). I cleared the p442 code and it hasn't returned after about 3 weeks of steady driving.