96 q45 throwing five codes, both TPS, TCS and CPS

[bluefeyd]

Have not been here in awhile my Q was running great. The last time I was here I read some old threads and fixed some issues by replacing my MAF and cam position sensor (CPS). Now, 6 months later ish, my Q is acting up again (bucking and bad fuel economy). I thought the MAF was acting up again, so I took it to Autozone and had them run the codes (check engine light was on). It threw five codes. 1210 (TCS), 1120 (2nd TPS, throttle position sensor), 0120 (TPS), 1705 (also TPS), and 0340 (CPS). I have the service manual (thanks to the forum) and am going to start working through the checks in there. Before I dive into that I figured I's drop a post and see if anyone had any good tips. I really don't want to drain my savings on buying a round of sensors (though TCS can stay broke for now, it lights up both slip and TCS off after RPM goes over ~4.5k and does not change with TCS button pressing). So naturally I am looking to fix these issues for the lowest costs possible.
Any suggestions or tales of similar experience appreciated. Thanks.

[black g50]

Is bucking immediate or does it take a while? Any shuddering taking off? Was new maf (new)?When it bucks,do you notice electric fan running?Having same symptoms,at a loss... ( tcs lights go off after changing blue relays under battery.)

[maxnix]

So naturally I am looking to fix these issues for the lowest costs possible. Any suggestions or tales of similar experience appreciated. Thanks.

I have bad news for you. You own a car that would b $80K in today's dollars. You get no further discount for parts or maintenance because it is old. You got your only discount for deferred maintenance when you purchased it.

OBD II is pretty specific, but still needs some experienced diagnosis. Better brush up and budget accordingly or sell it.

As a side note, I have been working on the FGY33 recently, and I have to say it is in many ways much better built than my BMW. The G50 and FGY33 Q45 are designed to last for a very long time if maintained well.

[black g50]

After thought.# days ago I noticed my cranking time has increased ,then when started a slight stumble for a sec,then smooths out.Looks like I have to check cps also.

[bluefeyd]

Well I ran a few of the continuity tests from the service manual, but not the ones to/from the ECM, because I have not yet taken off the glove box and accessed it before. The checks of connectors to ground and voltage all came out sat. Since I had recently changed the CPS with a new part (my MAF replacement was used, but it was not throwing a code), I posited that maybe there was a common link to the faults and proceeded to thoroughly clean the engine grounds (from the illustration in the service manual). Put it back together (there is a plate that you need to remove to get to the second of the two ground screws) and took it for a road test, with both in town and hwy driving. Almost shudder free, just a few hiccups at low speed shortly after starting. Also the bug where TCS off and SLIP were locked in has cleared. I can turn TCS on and off with the switch just like normal. Idle is coming in a little low ~550 rpm so I am considering adjusting that set screw (again using the procedure from the service manual). The check engine light is still in, and Autozone confirms that the codes are still in (they aren't supposed to clear them, but a shady one has been known to do it for ya). Looking to clear the codes, neg battery terminal didn't do it. The positive one is a pain to disconnect, but I will probably try it next.

[bluefeyd]

Maxnix I appreciate your position, but there are always ways to do things for less money. For example, looking up the codes at autozone and getting your own parts online and installing them yourself as opposed to running off to the dealership at the first hint of trouble (which I am certain no one here is doing). Yes I do realize that somethings are going to be pricey and involve hiring the skill sets of professionals. I hired a shop for my transmission rebuild a few years back. Still it doesn't cost a fortune if you shop around. This is my second Q (the first one gave its life for me in an accident) and my "daily driver" car since 2005.