risinganew

I recently bought a used 2008 Chevy Equinox and since then it has had several pcodes come up and all my googling is not helping me narrow down what the exact issue could be.
The pcodes are
P0300 (Random Misfire Detected - came up twice)
P0171 (System Too Lean (Bank 1))
P0420 (Catalyst System Low Efficiency (Bank 1) came up twice)
P0327 (Knock Sensor 1 Circuit Low Input (Bank 1))

The actual problems I'm having with the car is the idle runs high - between 1-2 RPM - and the acceleration feels like it sticks and the car kicks back when I try to accelerate, especially when I'm going up hills. When that happens, no matter how much I press down on the acceleration, my speed decreases, the RPM jumps all over the place and the car shudders. Once I'm going downhill or on an even road then everything starts to work fine again, but this is obviously dangerous and very scary - especially when I'm trying to get on the highway.

The person I bought it from said he'd replaced one of the fuel injectors recently and that the EGR valve needed to be replaced. I replaced the valve and while that helped a bit - the car isn't idling as rough or high, and it's not kicking back on the smaller inclines or hills - I'm still having a lot of problems.

I took it to AutoZone, they scanned it and it came back with the codes I listed. The top of the paper says it recommends "De-Ice Air Intake System", but I haven't been able to find anything online about how exactly to go about doing that. It also hasn't been below freezing where I live for about 2 weeks now, and this problem was occurring before winter hit as well, so I'm not entirely convinced "de-icing" is going to solve the problem, whatever that means.

I can't afford to take it into a mechanic or shop, so I'm trying to do the repairs myself. Any help or advice would be greatly appreciated.

Thanks!

ruley73

Which engine? Mileage? If it's the 3.4L, I'd make sure the plugs and wires are still good. Also make sure the plug wires are connected to the right coils. If that checks out good, I'd remove the throttlebody and clean it. You may have a clogged catalytic converter, but I think it's unlikely since it isn't a common issue with these models. You can temporarily remove the upstream oxygen sensor or the EGR tube to see if it runs any better. If it does the cat con is probably plugged.

Imogene Summerlin

I havent checked my throttle body because the code read ERG valve and tube it helped like that other person's but still the same I can be doing 20 mph and my RPMs are up to 2 1/2.its crazy I changed wires and plugs iv had this car a month now but other than this jurking going up hill it runs great SO FAR!!!

Gumby22

1) The knock sensor code needs to be the first thing to diagnose - a faulty knock sensor can cause random misfires and result in drive ability problems under load (going uphill), as well as set the P0300, as the PCM will adjust ignition timing based on knock sensor input.

2) If you have the 4 cylinder engine, remove the heat shield on the top of the exhaust manifold (may require O2 sensor removal) and inspect for a crack in the manifold. A cracked exhaust manifold will allow excess oxygen into the exhaust stream and set the P0171/P0420 codes. I specify the 4 cylinder because the cracked manifolds seem to be a common problem with them - I’ve replaced 4 of them on customer cars in the past year.

3) The “de-icing” air intake refers to a service bulletin GM issued regarding the PCV systems. Moisture is known to collect in the PCV tube and freeze, blocking flow and most often blowing out the rear main seal due to excessive crankcase pressure. Besides resulting in a major oil leak, this can also set the P0171 code due to unmetered air entering the engine via the PCV flow.

If the temps aren’t freezing in your area, just make sure the tube is clear by removing it and blowing compressed air through it.