My 06 cobalt has these codes can anyone tell me what they mean? Are they an expensive fix? p0446,p0455, p0172

Question edited for clarity and add CAPS.
Question move to Cobalt category.

It is dumping extra fuel.

P0171 code SS SC - Cobalt SS Network

CobaltSS.net https://www.cobaltss.net > forums > p0171-code-ss-sc-...
Mar 1, 2014 - P0171 is a fuel trim lean code. Meaning the car is having to add more than 25% of the normally asked for fuel to reach proper O2 sensor ...

P0171 code
Jan 14, 2012
P0171 code "Bank 1 system too lean"
Nov 9, 2013
P0171 on 2007 SS/SC - Stock
Jul 15, 2009
2.2 P0171 Fix??
May 7, 2007
More results from www.cobaltss.net

For those with the FAMOUS P0171 CEL - Cobalts SS

cobaltss.com https://www.cobaltss.com > threads > for-those-with-th...
About the FAMOUS P0171 DTC (diagnostic troubleshooting code). If the PCM detect a lean condition (roughly 15% leaner than stock or more lean), this code ...

Missing: 2.0. ‎' Show results with: 2.0.

P0171 Chevy Cobalt: Fuel Trim System Lean Bank 1

700r4transmissionhq.com https://www.700r4transmissionhq.com > p0171-chevy...
Jul 28, 2018 - It indicates that your Chevy Cobalt is running lean on the bank one side. It's the most common air/fuel mixture-related code. It's not the most ...

‎Definition · ‎Symptoms · ‎Causes

These codes all relate to fuel. As for the steering stiffening up, it shouldn't stiffen up if not used for a while. Check your tyre pressures, the tightness of the steering pump belt and level of fluid in the steering pump. If those are all fine, then a trip to your local workshop may be necessary.

Take it to a ASE certified repair facility ,they'll fix it up ! Don't just replace parts !!!!!

P0171 - is a lean code bank 1 -possible vacuum leak , low fuel pressure , plugged fuel filter ,
P0300 - is a random misfire code which is understandable with a lean code .
P0420 As the code description implies the P0420 code means that the vehicle's control module has detected that the three-way catalytic converter is not working properly (is not as efficient as the factory is expecting). Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases the catalytic convert needs to be replaced to fix the problem. If the P0420 code is combined with other codes, try fixing the other codes first
P0452 - EVAP Control System Pressure Sensor Low Input
P0446 - Evaporative Emission Vent System Performance
P0453 - Fuel Tank Pressure Sensor Circuit High Voltage
P1639 - PCM 5 Volt Reference Voltage Circuit Condition
P1653 - Power Steering Output Circuit Malfunction
P1651 - Fan 1 Relay Control Circuit
If you don't know what your doing take it to a repair shop before you waste your money ! You have a lot of problems here an I don't think the computer is bad , I'd say lack of maintenance ! You need to learn how to test thing's to fix them ! From the five volt reference voltage code , I'd say one of your sensors is shorted internally bring down the ref. voltage circuit causing the no start, but then again the 5volt ref. circuit in the PCM could be the problem . What you need to do is Disconnect all sensors that receive 5volt ref. signal one at a time an see if it will start . If I knew what year vehicle yours is I could tell you what sensors ! MAP, TPS , etc...

Code 172 means the O2 sensor is telling the computer the fuel mixture is too rich.
Code 455 is a large evap leak in the gas tank venting system, and code 442 is for a small leak. The engine computer pressurizes the fuel tank every few minutes to check for leaks. Vapor leaks (fumes) could escape into the air if the system is not working correctly.
Its possible the system is faulty and allowing gasoline to be pulled into the engine instead of it being vented thru the vapor canister.
You would need to find out where the vent leak is first.

I researched this and found the following information. Hope it helps: P0455 means a gross leak detected in the Evaporative Emissions System. Some call this a "gas cap" code, because the most common cause a loose or failed gas cap. But it could be caused by any vapor leak in the fuel tank, filler neck, or anywhere else in the vapor management system. If it isn't a gas cap, you will need tol take it someplace where they have a smoke machine that can find the leak using smoke.

A lot of times a bunch of Codes may come up and cover a lot of areas. It may be one of these Codes, it may not. And it may be None at all, and the system just has to be reset to put the light out.
As far as what the Codes (parts and/or) actually represent, Autozone, etc should have the meter that tells what those Codes are. Or ask the Dealer what the Codes mean, without agreeing that you are going to let them fix it but just trying to get an idea what to expect. Soemtimes they may want to charge you to do something like this, and sometimes you may wan to say goodbye. You may want to buy a Subaru. If you bring your car in to one of their dealers, whether you bought it there or not, they will take some info from you to get you into their system, bring the car in, put in on meters or whatever, tell you what might be going on, and not charge you anything whether or not you decide to get it taken care of there.
My Father owned a hunk of junk 1983 Buick Regal and every time I drove it the "Service Engine" lights came on. There was nothing wrong with the Car, and the light would eventually go out when my Father started driving it again.
Part of these problems are simply that Computers are machines, do what they are told to do, and only as good as the people setting them up. So, in this case, putting a computer in a Buick that they didn't even know what a "Spring and Suspension Rate" was, is the obvious reason things didn't work right, if at all.

All the P0300 codes are engine miss codes. The P0455 is a catalyst inefficiency code and the P0172 code is a rich mixture code. All of these could be caused by faulty oxygen sensors. What kind of car, engine size and mileage is it?

Fuel Sys, Driveability, Filters (Air & Fuel)
2006 CHEVROLET COBALT

02/01/2006 ELIMINATION OF FUEL FILLER TUBE FLAPPER DOOR 03/01/2006 ERRATIC FUEL GAUGE READINGS 06/01/2006 USAGE OF E85 FUELS IN GM VEHICLES - REVISED 06/01/2006 L61 ENGINE MALFUNCTION INDICATOR LAMP (MIL)/SERVICE ENGINE SOON (SES) LAMP ILLUMINATED WITH DTC P0171 "FUEL TRIM SYSTEM LEAN" SET 07/01/2006 TOP TIER DETERGENT GASOLINE - DEPOSITS, FUEL ECONOMY, NO START, POWER, PERFORMANCE, STALL CONCERNS - REVISED 07/01/2006 USE OF E85 FUELS IN VEHICLES NOT CERTIFIED BY GM AS BEING FLEX FUEL COMPATIBLE / AFTERMARKET CONVERSIONS OF VEHICLES TO OPERATE ON E85 FUELS 09/01/2006 397.pdf&btitle=2006 CHEVROLET COBALT&yr=2006">GM FUEL SYSTEM TREATMENT PLUS, FUEL SENDING UNIT CORROSION AND FUEL SYSTEM DEPOSITS - REVISED 11/01/2006 940.pdf&btitle=2006 CHEVROLET COBALT&yr=2006">ERRATIC FUEL GAUGE READINGS - REVISED 03/01/2006 USAGE OF E85 FUELS IN GM VEHICLES - REVISED 12/01/2006 TOP TIER DETERGENT GASOLINE - DEPOSITS, FUEL ECONOMY, NO START, POWER, PERFORMANCE, STALL CONCERNS - REVISED 01/01/2007 EMISSION RECALL - ENGINE FUEL INJECTORS - REPLACE 01/01/2007 LSJ, L61, LK5, L52, LL8 ENGINE - REDUCED ENGINE POWER, MIL/SES LIGHT, DTC P1516, P2135, P2138 02/01/2007 MULTIPLE DRIVEABILITY SYMPTOMS DUE TO CLOGGED FUEL INJECTORS, MIL/SES DTCS P0171, P0172, P0174, P0300, P1174, P1175 - REVISED 03/01/2007 MULTIPLE DRIVEABILITY SYMPTOMS DUE TO CLOGGED FUEL INJECTORS, MIL/SES DTCS P0171, P0172, P0174, P0300, P1174, P1175 - REVISED 05/01/2007 MULTIPLE DRIVEABILITY SYMPTOMS DUE TO CLOGGED FUEL INJECTORS, MIL/SES DTCS P0171, P0172, P0174, P0300, P1174, P1175 - REVISED 06/01/2007 <A href="http://arrc.epnet.com/autoasp/data.asp?sid=122357497&uid=s9193090.remote.autorefctr&type=pdf&ff=082000

THE 445 IS THE EVAP PURGE VALVE IT MAY BE BAD BOTH 446 IS SAME VAVLE YOU NEED TO SEE IF THE HOSE ARE GOOD ON THIS VAVLE MAKE SHERE NO CRACKS IF NOT PULL HOSES AND SEE IF SOMTHING IN VAVLE ITS NEAR THE CANSTER AND THAT IS NEAR THE GAS TANK UNDER CAR PUT CHECK GAS CAP MAKE SHERE ITS TIGHT HOPE THIS HELPS