customit

Hi Guys,

I have recently purchased a 2001 Firehawk. I have slowly been going through it replacing parts that have thought to have been dodgy - suspension, steering parts mainly.

I thought the vehicle wasn't running quite right. I had a basic tuner/diagnostics plug device (Jet DST) and used it to diagnose the o2 sensors although working I didn't think were quite right - this device doesn't read fault codes...

Anyway I have replaced them with brand new ACDelco AFS123. All was ok. until I got to 40+mph, the car seems to run fine as before, but I got MIL light on... I decided to get the OBDLink MX and the app on my phone. I have read the codes and the other diagnostics information is gives and these are the results.

O2 Sensors Bank 2 Sensor 1 TID $70
min=47 max=255 value=36 (value shows in red)

O2 Sensors Bank 2 Sensor 1 TID $81
min=9 max=159 value=0 (value shows in red)

Stored codes = P1133 P1153
Pending Codes= P1153

It then gives me the following freeze frame information I guess relating to the pending code.
Freeze frame dtc = p1133
fuel system status = closed loop
calculated load value = 12.94%
engine coolant temp = 176F
short term fuel % trim - bank 1 = -1.56%
long term fuel % trim - bank 1 = -2.34%
short term fuel % trim - bank 1 = 1.56%
long term fuel % trim - bank 1 = -2.34%
intake manifold absolute pressure = 8.7psi
engine rpm = 1489.25
speed = 59.65mph
mas air flow rate = 4.8lb/min
throttle position 20%

obviously I was right about the o2 sensors not being right, as now replacing them has brought up an actual fault with something else.

Please help.... what is the information above telling me is at fault

thanks in advance

Mercier

iTrader: (15)

Here is some interesting reading for you:

http://www.ls1.com/forums/f6/p1133-p1153-108815/index2.html

Those codes look to be codes for O2s not switching as fast as they should like they aren't getting hot enough regularly.

What's not stock on the car? Have you performed a basic tune up with MAF, IAC cleaning?

customit

The car is a firehawk. So came from slp with some mods not standard from factory.

It's got long tube headers and the cold air force intake. I think but not 100% has different cam from slp but I don't know this for sure. The previous owner hasn't modified the car it is as is from slp.

There wasn't a problem before apart from what I felt to be a minor judder / hesitation during light acceleration at low speeds. Hence why I decided to change the o2s. The judder has since gone and is smoother. It's still using more fuel then I think it should so I think something else is old and not telling the computer something correctly, changing the o2s I feel is the start of a long journey changing stuff.

The car has 81000 miles on it. And with the long tubes and cold air intake straight from slp I understood they would have reprogrammed the vehicle as such.

Mercier

iTrader: (15)

Clean the MAF with proper MAF or electronics cleaner. Not just the exterior...the little wires inside. It's a maintenance item and since this is the primary device that tells the computer how much air is entering the engine, a false reading from dirt on the sensor wires can cause all sorts of funny business. Also worth changing the plugs if you haven't recently.

Russ K

iTrader: (1)

P0133, P0153, P1133 and P1153 are very common codes when LT Headers are installed. Just set them to no error reported & uncheck the ses box in the tune.

Russ Kemp

customit

This is what I have read too. But.... This is an SLP tuned car. LTH are part of what they do, surly they won't let a mod cause such behaviour out the factory. GM won't let that fly! !!

I don't want to put the old sensors back as I think it's just masking an actual problem.

As part of the things I have been doing since I had the car due to the hesitation (very very minor kangaroo) at slow acceleration I have removed the honeycomb filter from the maf and cleaned it. Plugs and leads have been replaced, new fuel filter and recent oil and filter change too. I had even put a new alternator on it as it was starting to leak AC voltage.

Are ther no other monitoring tests I can do to ensure they are reading on the range they should at certain conditions.

I'm going to get some spark plug heat shields and cover the front o2 sensors and see what happens over the weekend as I reset the codes last night and the journey into work brought up P1153 code fairly quickly.

Russ K

iTrader: (1)

The 2001 Firehawks used stock manifolds. Just had a cat back exhaust system.

Russ Kemp

Burken01

iTrader: (88)

^ yup

If there are longtube headers on the car then it wasn't done at the factory..

Somebody must of installed them before the guy you bought it from got his hands on it.. And got lied to

trey0153

iTrader: (3)

and if they didnt use the corvette o2s there prob not gonna read rt because they dont get hot enough being further down the collector than stock locations.i belive there bosch 13111s for the corvette ones.

Russ K

iTrader: (1)

Corvette O2's are not the answer. The codes need to be set to no error reported & uncheck the SES box in the tune.

Russ Kemp