SpadedOne

iTrader: (1)

Resently my car started having a really strong gas smell out the exhaust when I first start the car up. Usually goes away in a few minutes. I've noticed I'm getting horrible gas mileage now to, like maybe 10 miles a gallon. No check engine lights and no codes. Where should I start to try and solve this? TPS? Plugs?

Plugs and timing belt where done with 172,000 miles in 2007, and now has 191,500. It runs really good and smooth. Slight hesitation occasionally, but that seems pretty common.

Ali SC3

iTrader: (10)

Check/replace your oxygen sensors if you have never done it, they are recommended every 60k, and after 150+ they are definitely dead and probably not even registering anything.
If it is your o2 sensors and you fix it that slight hesitation should also go away, an SC4 runs a little rich most of the time anyways, but when your o2's are dead and you are running really rich as in no trims at all, it will loose performance, loose power, and loose MPG.

If you hadn't said it ran really smooth, I would also say check over the ignition stuff alot of times one of the 2 coils will go out, it will run on just 4 instead of 8 suck down gas and have general bad performance. problem is these motors run so smooth alot of people cant tell if its on 4 or 8 so they check everything else.

snakehead

iTrader: (1)

Check for leaky injector , bad o ring ...

SC400slide

iTrader: (11)

O2 sensors would do this. I suggest you replace the front ones.