So, after a long search, I found my 4runner and bought it from a private party just this last Sunday morning. The chassis has 171,000, and cylinder work and a ton of new parts (radiator, timing, water pump, fuel pump, comprehensive tune-up, etc.)

Had a mechanic from work spot check it, and he also hooked up a scanner before buying it, and it showed no problems, errors, etc.

Wound up paying $4000 for it, and all seemed well mechanically over the last week, and I was absolutely pleased about the car, as it's just clean throughout.

So last night I was running low on fuel (gas light came on), got 1/4 tank of mid-grade fuel at a Chevron, drove 3 miles home, and all seemed fine.

This morning, I get in the car, and the check engine light stays solid, and it seems like a bit of a power loss. Merge onto the freeway, and I practically have to floor it to get up to 60 mph. Eventually the power seems to return, but it is clearly running a bit slower and the CEL is staying solid. Idle seems ok, and car isn't shaking or smoking, and is holding fluids OK. The oil seemed a little low, about 1/8 inch below full.

I'll be getting the error codes on my lunch hour in a bit, but can anybody here offer some insights? Is it a sign of impending doom here? Thanks for any help!

Sounds like a possible p0171. At this point it could be a couple different things (plugs, wires, maf sensor, o2 sensors, vacuum leak) just wait until you get the code/s and trouble shoot from there.

Are you sure you put the fuel cap back on , or on properly ?

Po420, plugged kitty. But get the code first.

I checked it this morning, and it was on there tight. Pulled it off and put back on to be sure, started back up, and the CEL is still on.

Second that, w/o checking the codes you are left to "spitball" it....If it is not possible to read the codes, I'd pull the MAF and clean it out, going from there

Ok . Dont you have to clear the code first though ?

I had the same thing happen and the cap actually needed replacing . But I needed to clear the CEL as well .

Funny as mine was right after purchase too

Fuel cap loose may cause the evap leak, but not the power loss....fouled plugs or wire problems usually cause intermittent issues, stumbling and so forth...The MAF would cause a consistent misreading of the Air intake leading to a consistent power loss. A fuel supply issue could also cause a consistent low of power....pulling the code would be very revealing...

thanks for the replies everyone...i'll post the codes as soon as I get them. the guy i bought the car from claims he'll scan it and fix what the problem is - "if it's a quick fix" (great) i see a catalytic converter replacement for this thing is like $600 just for the part....I know you should expect stuff to go wrong with an old used car, but I thought I'd get at least 1 week of driving out of it before having to throw down that kind of money, good god.

It happens! very cool of the seller to offer that. The one I bought developed a issue on the way home from Texas to Cape Cod.

Hope it all works out

If it does need a cat, look online for one of the CARB approved cheap replacements. You can order them from Napa, Oreily, etc and have a local muffler place install. just my .02
Good luck

Thanks for the tip - think I jumped the gun on the Cat replacement - it looks like the one I saw online for $550 isn't even legal in California...but now I'm wondering if there are 2 Cats on this thing I have to worry about?

If originally sold in Cali, based on the year yes I believe 2.

I wouldn't order anything until you pull codes. It might just be a dirty MAF, a free 10 minute fix.

Error is P0402...seller claims not a big deal? says something with a valve