My 2001 Volkswagen New Beetle GLS had recurring OBD2 trouble codes, P0171 and P1582, coming up over the summer. Reading other threads, I popped the hood and found a short piece (~1 foot) of disintegrated hose on the left hand side of the engine block (American passenger side). I pulled off the hose clamps and what little cloth like tubing remained and replaced the tubing with black silicone tubing purchased from an eBay auction with these specifications:
The new tubing fits like a glove and the listing is still available: https://www.ebay.com/itm/161551221275.
I’ve had this hose installed for almost 4 months with exposure to hot (90 degrees Fahrenheit) and cool conditions (10 degrees Fahrenheit) and my 2001 New Beetle GLS is purring like a pussy cat again. Even better, the trouble codes have stopped.