jdoostil

iTrader: (2)

my heat isnt hot. where should i start troubleshooting? everything blows properly, and the a/c is ice cold, just not hot like it once was. i havnt ran the heat since last year.

also, im throwing (intermittently) a 171 and 174. system too lean bank 1 and system too lean bank 2. o2 sensor? other than that, car is running great.

thanks guys!

Bluestreak

Does it produce poor heat in all ventilation settings? The only thing I can think of is the blend door might be sticking.

I doubt its the O2 sensors since it's on both banks. It's more likely something to do with fuel delivery common to both banks, such as a clogged fuel filter, or perhaps a failing fuel pump, which can be a result of pumping against a clogged fuel filter.

67RSCamaroVette

iTrader: (63)

Check coolant level. Heater is the first thing to go if the coolant is low.

+1 for fuel filter.. do a pressure check at the rail and rev it a couple times. Could also be pump. Stock tune?

Bluestreak

I thought about this, but could the coolant get to a low enough level to affect heating without the warning light on the dash illuminating? Just curious. I've had the coolant level sensor fail altogether (which just turns on the idiot light if the sensor is stuck at the low-level setting) but I never had my coolant get low enough to affect the car's operation.

jdoostil

iTrader: (2)

yea the heat isnt hot. doesnt matter where the setting is. is the fuel filter a simple swap?

Bluestreak

I'm assuming you checked the coolant level and it was satisfactory...?

Yes. Turn the key on but don't start the engine, then pull the relay for the fuel pump and start the car. Allow it to run out of gas and stall. This will depressurize the fuel system and take much of the fuel out of the filter. Then you need a few rags, a fuel disconnect tool kit (cheap hard-plastic ac/fuel disconnect tools are available at most auto part stores) and a new filter. You'll need to get the rear of the car up in the air to get at it comfortably.

skat

iTrader: (3)

Mass air flow sensor if the car is not running rough then check it and clean it, reset the light and see what happens.

http://www.obd-codes.com/p0171
http://www.obd-codes.com/p0174

Fuel filter is super easy, instruction above are very good. I've never needed the disconnect tool on my car I just pinch the white coupling with my fingers.

Heat, thermostat could be stuck open. Change it, it's easy and will eliminate one thing. If it does not fix the problem suspect the blend door, assuming the coolant is ok.

Phil'sC5vette

iTrader: (4)

You may have a little air leak and unmeasured air is slipping passed your MAF.
Just for sport, spray your MAF with some cleaner, and make sure when you button it up, the seals dont leak.