I have a new tuscany XTE with the 6.7 engine, the air intake is high near the rear of the coach. My problem is the filter minder always reads high, with a new filter it still reads high.
In your case check the filter minder, it probably has not been reset. If it has been reset the coach will needs to be run at highway speeds to check the condition of the filter or pull the filter and check/replace it. The location of your intake looks like it could pick up road spray in rain and snow. In any case the filter minder is a good indication of the filter. Looks like in your case the filter is easy to get to, mine is a big PITA.
Also what engine does it have? 6.7 or 8.3, my 6.7 is rated at 360hp and does very well pulling a 3500# trailer. The coach looks in good condition, you need information from more owners.